Fast Math Tricks - How to multiply 2 digit numbers up to 100 - the fast way!

[@sayakdiptapaul]

I hope its not too late to post a comment, sir, you cant imagine how far your lessons are reaching and how many minds are they changing , just for you. thank you, from the bottom of my heart.

[@neena_nalathra4036]

same

[@apriltwenty4945]

Agree I am an accountant an learning this now. 🙏🏽

[@1polyron1]

@@apriltwenty4945 Do you like accounting?

[@ZauligChan]

Thank you from Florida

[@Appelsientje284]

I agree

[@6maniac6metal6]

To anyone wondering what to do if your second set of numbers comes out in double digits, you put the left number in the blank space. Then you finish like normal simply adding that number and the one that would usually be in its place, and simply carrying the extra if those number come out over 9. Example: 12 x 15 1x1=1 and 2x5=10 So that’ll look like 110 Then 1x5 + 2x1 = 7 Now we take that 7 and add it to the 1 in the middle position and there’s our answer: 180 And to do big number you can just combine that with what he says in the video. Example: 79x88 7x8=56 and 9x8= 72 So we have 5672 Then of course 7x8=56 and 9x8=72 56+72=128 We then take that and combine it with our previous number 128 5672 Add that how it’s lined up there and you get 6952, and that’s our answer Hopefully this helps someone!

[@hahah2804]

I dont understand why this guy didnt explain this. Helped a lot

[@L1nkkkkk]

How do you combine 128 and 5672?

[@riansevilla8845]

@@L1nkkkkk he first add the 67 and 28 then the remaining 1 is add to 5 which makes it 6 95 2

[@williamporter8463]

THANK YOU FOR THIS. Not quite the way the video explains it. I was multiplying 29 × 47 and the video method wasn't working. This method works. Thanks!

[@Msmaxine130]

Yes!! Thank you! I literally just asked this question … then saw your post. 😆 Thank you!

[@jimc12]

I'm 38 years old and not very good at math. I blame myself out of anyone for this. I've watched a few of your videos so far and have learned more in regards to math than the past 36 years of my education. You are making math fun for me. The only thing that is holding me back now is mental math and doing these in my head. I'm working on that though. Thank you!

[@DavidG-kv8wm]

Born and raised in the United States 🇺🇸 i love my country. But im 56 and now learning a way better a quicker way from you has left me like WTF! When it comes to our educational system. And very grateful and appreciative to you sir. Thank you very much

[@Bookish1995]

@Otto von Bismarck not funny, try again

[@doge2889]

good all you need to know is that the earth is flat

[@hopehouston5732]

Right but as long as you have scratch paper is all that matters we all put our jeans on,one leg at a time .. if you can do it with no calculator you are the bomb..lol

[@Migixkem]

School system was always nothing in the first place

[@erinn828]

Oooohhh, this is FOIL method (First, Outer, Inner, Last). I did not realize that cause you explained it so well, and made it look so easy. Thank you for this sir!

[@tanvirhoque4956]

Some times he just sounds like he is gonna burst into laughter😂

[@lekronss]

I was expecting this to be super complicated, but after watching 5 minutes of this video, I could solve each problem in around 10-15 seconds. I'm super happy right now.

[@zadinzadin]

cool

[@Calculus23]

Bruh I solve it in 5 seconds using normal method

[@NiqueloAncets]

@@Calculus23 Good for you, but this is for people who can’t mentally calculate fast

[@dedricblowe5574]

Where the heck were you when I was in high school... I’ve watched 4 of your videos and I see teachers don’t teach these because once you get it... you don’t need anything else... you just became amazing.

[@ritabrebre]

bruh I just graduated highschool and I'm only learning this now lmfao

[@xrank1110]

Same

[@brayntcastellanos7125]

Hahhahahaha same bro

[@ayanokojikiyotaka4580]

LOL

[@fineasgoodasfine134]

bro im a sophomore in college and just learned this

[@KillersBF]

Studying for my GED 😔

[@MrJtheviper]

I am in school and the kids in my class look at me like i was from a diffrent planet when i said the answers correctly over and over again.

[@LearnMathsFree]

+Jtheviper Cool!

[@sunilpatel4902]

Jtheviper me to

[@__-vj6fu]

Jtheviper my teacher called me to go and solve the question at the white board and the class looked at me like "ugh it's this bitches turn" (litter ly) you guys get that pun?(it's pretty bad what am I doing XD)

[@yousufhassan6962]

Turbulent

[@dcgarg2895]

Is to fast ta simple multiplication nal hi ho janda hai

[@AmyJessicaW]

You, solely, are going to get me passed my ITT Professional Numeracy Skills test! For that, I thank you!!!!

[@z7zss1]

So did you passed?

[@user-hd6xc1xn9d]

Tecmath, I am a viewer and I love your math videos! One thing I hate though, is how you never explain it. Other kids at my school ask " Wow, you're good! How do you do the strategy?". I tell them the strategy. BUT, they wanna know WHY IT WORKS! So please explain why it works if it is less than somewhere around 10 minutes to explain. PLEASE like this so he can SEE IT! - A Student In Math

[@jozsefsalagvardi7694]

If you want to multiply two numbers between 9 and 100 with this method you have to know that what means if the number is on the first or the second place (and etc.) in the ten numerical systems. For example: 12 X 34 equal / can be written as (10 x 1 + 2) X (10x3 + 4), or generally (10a + b) X (10c + d). Let us multiply these numbers: (10 x 1 + 2) X (10x3 + 4) it will be (10x1X10x3)+(10x1X4)+(2X10x3)+(2X4), or generally (10a + b) X (10c + d) = 10aX10c + ( bX10c + 10aXd) + bd. …. as _X 100 + _X 10 + ... _X 1 The result has a part as 100's from the 10aX10c, has two parts as 10's from the bX10c plus the 10aXd (as sum of cross-multiples) and has one as 1's from the bXd values. The result will be 3 or 4 digits only. I hope that this helps.

[@Doc_Bavarius]

It makes use of basic algebra if a x b = c is the question and a and b are any 2 digit numbers. Then a = the sum of it's parts eg 10s + 1s. Eg if a = 25 it is the same as (20+5) In algebra if (d+e)×(f+g) = df+ef+eg+ef Eg 24×53 = (20+4)×(50+3) =20×50 + 4×50 + 3×20 + 4×3 Notice 20×50 is the first part you put down ie the biggest number. 1000. But in order to make addition easier you leave the last 2 units blank therefore 10_ _. Add in the units 3x4=12. And you get 1012. But you still need to add 20x3 and 50x4=60 and 200 or 260. Lose the zero and you have 26_. Line them up. 10_ _ 26_ 12 1272. That's what you do to prove it. But you take shortcuts in your head to get to the answer. Condensing and compressing it to be easy to understand.

[@dietrevich]

Hi!, I know it's a late response but anyway. The reason it works its because it's an application of the distributive law. So for example 22x32 it's the same as (20+2) x (30+2). He is using it out in a summarized way.

[@khajaraheemkhan8509]

Bro what about 46 into 59

[@williambarnes1397]

@@Doc_Bavarius Not sure if you can edit your otherwise excellent comment but I think you'll find (d+e)×(f+g) = df+ef+dg+eg

[@stevenhaskell9025]

This man has taught me more than my school

[@rahuimaru8983]

🤣🤣 same I'm like wtf was my teachers even teaching me

[@小麻雀-y2n]

Same

[@nutcracker2916]

Me too. Love your profile pic.

[@Study-ez6cf]

Me too😂

[@Liapjr]

seriously?? last time im in school was 4 years ago now im 17 and im suprised

[@raunichey]

I just got a job that involves a LOT of mental multiplication and your videos are saving my LIFE! THANK YOU! :D :D

[@paulhemming5376]

Which job requires mental multiplication a lot

[@davidlewis1680]

I suffer from maths dyslexia and anything to do with maths make me come out in a sweat . You sir are a great teacher , love these maths tutorials. Thank you so much . I’ve subscribed

[@djamilac9556]

I used to leave my math exam paper blank. I could not understand a thing.

[@user-tt8wf6cr3g]

@@djamilac9556 lol

[@bellakhut5579]

I learnt this in Primary School and the teacher called it the “ Rainbow “ method. ( P.s. you do the best math videos )

[@beverlyfrancis8433]

Ok.

[@noxy_xoxo]

Lol me too 😂

[@carolynroberson8407]

No one ever taught me this in school. Love your videos.

[@99oildrops]

@@carolynroberson8407 I wish I knew this. I was terrible at math. lol

[@petslife2411]

Nope he is the worst teacher

[@christopherwilson6527]

Why are we not teaching this in school?! Ive now gone from not knowing my times tables to multiplying double numbers! Awesome thanks!

[@HomeOnlineMathsEducation]

I got 704 3213 and 4182 in less than 2 minutes and I solved them mentally....☺️ Thanks a lot for this method 😄

[@BaroShirts]

Are the math lessons from 2011 helping? “Yes”

[@ivickyvlog352]

MiguelGaming ReadyChannel lol

[@kiwi12315]

Wow this was made in the year i was 1 and i am 9 right now wowwww this is old and yes it helps🙂

[@luipirronecook8474]

i keep getting that AD

[@dhennied]

Ulol

[@klimankhmeron7636]

Some of the lessons still helping from 2000 B.C.

[@pratimamehta2613]

this video is really really helpful this time i got 99.7 in maths because of my fast multiplication compared to last time when i got 80.5

[@LearnMathsFree]

+Pratima Mehta Congrats!

[@ZingZangOliver]

Interesting but how do you get a 97.7?

[@K9sual]

+ZingZang Oliver I had a 103% called extra credit and paying attention

[@ZingZangOliver]

+Doom Patato Oh, i was just a little confused because in my school we dont do extra credit.

[@aileenalien-ji4sg]

How did u get a 99.7? My teacher saids it's impossible to get a 99

[@nakulchauhan8776]

This is absolutely the most helpful thing ive seen being in highschool.

[@elise-g05]

This helps me a lot now I can spend less time trying to figure it out.

[@insideful8529]

@Adib Farhan 480000

[@somxr_738]

chiaroschurros it’s index, not multiplication. multiplication sign is *

[@anzalh8339]

Your just an amazing teacher who inspires confidence and makes learning maths FUN!

[@herrkonghmongvue8108]

Love this guy he's getting me work up about math again

[@Lukeyboi1211]

You are so helpful because I don’t no how to do the column method for 2 digit by 2 digits so that’s really helped me out. Thanks😃

[@julianasantiago]

TecMath this is awesome!!!!! I'm feeling like a genius! And I can listen to your accent all day! This is exciting

[@bambispoon4305]

What happens when the units part of the answer is 10 or over? Lets say it’s 12 . Do you write down 2 in the units and then add the 1 to the tens column?

[@Amxxh1]

@@bambispoon4305 what?

[@broisthatdadog8983]

This man deserves much more than 1 million sub

[@warrenrgarey]

I love these videos. Thank you for sharing how to do seemingly complicated sums, easily. THE QUESTION REMAINS, WHY WERE WE NEVER TAUGHT (AND STILL NOT TAUGHT) TO DO MATHS THIS WAY IN SCHOOL?

[@itsoneAM]

Thank you so much for sharing this! Reconnecting with the old math fear in my 30’s and truly appreciate these methods

[@JoseGonzalez-ct5vz]

If you got 4 digits after the two first calculations, the use of the "_" must be avoided. e.g. 75x64 7x6=42 and 5x4=20, then you got 4220. (7x4)+(5X6)=58 4220 58 4800

[@aliatabassum6126]

Jose' Gonzalez, thank you for explaining. I am coping your answer to the people who have disagrees.

[@mariafe7050]

You mean if you have 2 digits from the products of the ones places

[@mariafe7050]

For example: 25x25 2x2=4 and 5x5=25 We have 2 digits in this product so don't use the _ 425 (2x5)+(5x2)=20 425 20 625 The answer is 625. If you used the _ it would look like this 2x2=4 and 5x5=25 4_25 (2x5)+(5x2)=20 4_25 20 6025 There would be an extra digit which we don't want.

[@Theismadsen.]

@@mariafe7050 how would you solve 57 x 17?

[@julienielsen4462]

@@Theismadsen. I figured it out if you get a double number on the last part of the number use that first digit to add to the middle.

[@alihaider51006]

Thanks brother for helping in such an easy and interesting way , it really made me tension free for my child's math multiplication problems that he has to solve without working, thanks again👍

[@doge2889]

L+ratio+thumbs+nothumbs+nomilk+toomuchbananas+Quadraticformula+bingbong+bin7gchilling+bing

[@leydicanche6240]

😊😊

[@gazclint1]

Wish I’d have had you as my maths teacher when I was at school

[@abeastgaming9600]

This is what my 3rd grade teacher took 1 year to teach and you taught me in 6 min 26 seconds, bravo

[@pepshaven6520]

I've been testing myself with these to lock it down in my mind. I tried a tricky one - 59 x 33 where we have to employ a trick you didn't show and I'm delighted to find I actually got it right! Yay! I can do math!

[@blenderanim8or]

Peps Haven - What was the trick? I tried 83X24 and did not come up with the right answer.

[@pepshaven6520]

@@blenderanim8or It's a little hard to explain but 15 x 33 works out to 15 _ 27 at first step. Second step it's 15 + 27 = 42. Third step is where you have to add. So...first number is 1, Second number is 5 + 4 (from the 42) making 9. Third number is 2 (plus the 2 from the 27) making 4. Fourth number is 7. Full number is 1947. In this video, he doesn't talk about adding carry over's at all. See if this makes it easier. 83 x 24 First step 8 x 2 = 16 3 * 4 = 12 16 ___ 12 Second step 8 x 4 = 32 3 x 2 = 6 32 + 6 = 38 Third step - where you add carry overs. Start with 1 6 __(38)__ 1 2 First digit 1 Second digit 6 + 3 (carried over from the 38) = 9 Third digit 8 + 1 (carried over from the 12) = 9 Fourth digit 2 Total: 1992

[@blenderanim8or]

Peps Haven That helped a lot! Thank you, I knew there was something I was missing there. And thank you for being gracious and not snarky like so many on this.

[@pepshaven6520]

@@blenderanim8or You're welcome. It took me a while to figure out what I was doing wrong too until I twigged. :)

[@nilupilu]

@@pepshaven6520 thanks so much, i will mention u here

[@DormFoodies]

This is Amazing! Thank You Very Much!

[@dennisburke199]

Thank you for helping me refreshing my math skills. I greatly appreciate it. Sure wish I had a math teacher like you growing up. Chances are I wouldn't have despised math as much. Thanks again!

[@doge2889]

bing bong

[@ethanpabonita6692]

Lol

[@yohannemohamad1949]

and this is why it has so many views than other math multiplication

[@HomeOnlineMathsEducation]

I am happy to know this easy method Sir.....☺️ Thanks so much for the tutorial 🙏

[@prasannaanna390]

I'm a banking student it is really helpful

[@zeefixdealwith-itgames480]

YOU HELPED ME DO MY HOMEWORK BECAUSE WHAT THEY DO IS SOME COMPLICATED CARYING OVER like 10 times u saved my time

[@zeefixdealwith-itgames480]

I liked and subbed

[@obi-wankenobi9088]

You... good sir... have earned a subscriber and a LOT of likes because I’m probably might watch all you’re videos since there really helpful

[@sharpgames2062]

I would have failed grades without the internet THANK YOU!

[@III_BLASTER_III]

You're a great instructor. Thanks!

[@carlsononly]

Just one thing. The results of the second numbers being multiplied are single integers. I have practices where the product of the second numbers are two integers. I found that if you add the first digit of the product from the second integers to the sum of the products from the first and second integers (consecutively) it's correct.

[@undercoveragent9889]

Well, taking 26 x 86 as an example, the first stage of the calculation, (6 x 6) yields a result of 36. So, instead of a '_6' as shown in this video, you would have a '36' there instead. The next stage, (2 x 8) yields '16' giving us an intermediate result of '1636', right? In stage 3, ((2 x 6) + (6 x 8)) yields a value of '60; add that into the '1636' as demonstrated in this video and you are left with '2236' and the correct answer. :)

[@twesiimemaurice8846]

@@undercoveragent9889 try 94 x 36. It gives a wrong answer

[@kb8026]

@@twesiimemaurice8846 yea this track doesn’t work there’s actually a lot of answers that don’t work with the equation.

[@user-hl4hf8yz1k]

How is it wrong?

[@theforgetfulnugget8971]

I swear this men sounds like he has so much confidence in me, and i don't even know him.

[@karenmcardle142]

9

[@stvivianne8820]

Your voice was so good had to watch it again.

[@quantumking1724]

The reverse FOIL process, that's genius!

[@KeisCore]

Im a student and every friday he would take us a fast multiplication i memorize the multiplication table and i know how to solve multiplication but it takes a minute before i solve that's why im here to learn how to solve multiplication fast and also to improve my mathematical skills i always watch your videos and it thought me many things and also improve my skills,thank you very much sir you're the reason why im top student now.

[@AhnastasiaRose]

You sounded so excited solving the third math problem 😂 Even I started to get excited and I don't even know why, I hate math 😂

[@teklitbrhane8652]

thank you so much. I have learned everything for your video the system of the math.

[@sir_jollibee]

Thank you so much for teaching and explaining things so thoroughly! I just showed off to my class and they were really impressed. I then taught them everything I learned form you, and it helped our class win the title of Best Class in Mathematics! Now I just need to remember these methods and not mix them up with all the other concepts u have taught 😂 Edit: By the way, I'm now like literally top 3 best in mental math and problem sum solvers thanks to you! Also lots of thanks to my math teacher in school, she teaches and explains things that can be understood almost immediately by the whole class; like you!

[@peytoncastillo4508]

Give this guy a medal

[@KhubaibKamran]

If anyone else is wondering: For values like 66 and 44, When you do this method, you get the answer 28824, right? So what you do here, is that add the last '2' to the next digit, which would give 8+2= 10, then add that one to the next digit, you'd get 2904, which is the correct answer. Hope this helps you ;)

[@luth.1]

thanks so much for this bro

[@ibrahimkuttypp2837]

25*45 pls do this using the above method

[@aatishom9848]

I love this video very much!!!, You have made multiplication simple to me!!! THANK YOU :)

[@DestinyQx]

(51)(63) = (50 + 1)(60 + 3) = 50*60 + 1*3 + 50*3 + 1*60 = 3000 + 3 + 150 + 60 = 3003 + 210 = 3213 Open Letter to Educational Systems: teach kids how to do this fast math trick.. the reason why it works is because of distribution.. something that is fundamental for high school algebra.. teaching 4th graders how to multiple like this.. will let them naturally understand how to distribute later.. and we can leave FOIL to mean what it originally meant as a verb (to prevent from succeeding)

[@treebytheseaside]

Thanks so much for this video. I have been wondering how to do these questions and now I know!

[@KX36]

oh my god where were you when I was in school!

[@archanasingh.2511]

Yeah, I use the same technique.

[@olatundeakindeleroberts5369]

It's doesn't work with 24*21

[@LowKDR123]

@@olatundeakindeleroberts5369 it does

[@LowKDR123]

@@olatundeakindeleroberts5369 504

[@brenzmona-taofinuu2043]

You were right in saying that probably half of us watching aren't even at school, I am one of those people haha

[@helloareyouokay9842]

Dude why tf doesn’t my school teach this 😭😂

[@bustergundo516]

Because they want you to struggle and get headaches.

[@DARKNESS-vm2og]

@@bustergundo516 ikr

[@chglubb]

I don't know what you have learned in school to solve this - but I have learned a way which is equally fast and which you can easily transfer to numbers with 3 or more digits... By the way: doesn't everybody use a calculator to solve this?

[@khalidsheikh1581]

@@chglubb booo

[@polarized8150]

@@chglubb well you have a nice school ig cause almost every school doesent teach this

[@Breaasofinee.]

Thank you so much I am in the fifth grade and I didn't know how to do two-digit multiplication facts and now I finally had Iman to study thank you so much I subscribed and turned on all notifications ty

[@jujucasar2003]

Its just simple distribution ADDITION 1st term: make both 2 digit numbers end in 0 2nd term:"first number multiplied by 1s digit of the 2nd number 3rd term: 2nd number ending in 0 multiplied by the 1s digit of 1st number To c this if u have 30 X 20 then u have remaining another 31 and 1 31X21 = [(30)(20) + (31)(1) + 20(1)] = 600+20+31 = 651 43 X 21= [(40)(20) +(43)(1)+ 20(3)] = 800+43+60= 903 63X42 = [(60)(40)+(63)(2)+40(3)] = 2400+126+120= 2646 U can reverse the rolls of the 1st and 2nd number 1st term: same thing 2nd term: first number ending in 0 multplied by 1s digit of 2nd number 3rd term: 2nd number multplied by 1s digit of 1st number 31X21 = [(30)(20)+ (30)(1)+21(1)] 43X21 = [(40)(20) +(40)(1)+21(3)] 63X42= [(60)(40) + (60)(2)+42(3)]

[@jujucasar2003]

+Justin Casar U can also use subtraction in distribution when the 1s place is really high Its just Simple distribution SUBTRACTION (only difference is you ROUND UP when simplifying the 1s place to 0) 1st term: same thing 2nd term: first number multplied by 10 - 1s digit of 2nd number 3rd term: 2nd number ending in 0 multplied by 10- 1s digit of 1st number 39X28 = [(40)(30)-(39)(2)-(30(1)] = 1200-78-30= 1092 U can reverse the rolls of the 1st and 2nd number 1st term: same thing 2nd term: first number ending in 0 multipled by 10- 1s digit of 2nd number 3rd term: 2nd number muliplied by 10-1st digit of 1st number 39X28 =[(40)(30)-(40)(2)-(28)(1)= 1200-80-28 = 1092

[@OHLeeRedux]

Yeah. All that useless nonsense just to make yourself look smart. This guy presents a simple, straightfoward method for doing multiplication, and you turn it into a great big stinking pile of who-gives-a-shit. Fuckwit.

[@KayKay-vc5uz]

+OHLeeRedux lmao

[@yannaangelayulin9585]

+OHLeeRedux yeah ;) I had nosebleed while reading this guy's (J. Casar) comment lmao

[@imtiazhas9]

scary :3

[@tivmego]

Hello, does anyone know how one could solve 127 x 23 using this method? The trick only works with 2 2-digit numbers. How about the multiplication between 1 3-digit numbers and 1 2-digit numbers ? Has he taught any trick regarding this?

[@TofuFiesta]

I'd say just first do it with the 27*23 and later multiply 23 with 100 and add it up.

[@erggish]

tivmego It's difficult to explain this method of his in words or maths, but I'll give it a try. Suppose that XY is a number (eg for X=2, Y=3 this number will be 23) and WZP is another number (eg for W=1, Z=2, P=7 this number will be 127) So X,Y,W,Z,P are just digits. Now take and write: (XY) * (WZP) = (X0+Y) * (WZ0 + P) = (WZ*X) [00] + (X*P +WZ * Y)[0] + P*Y where I put the zeroes in [ ] because what he does is write for each zero-brackets an empty slot: _ _ _ in the 1st slot he puts the number next to [00] : WZ *X (the first numbers of your choice) in the 2nd slot he puts the number next to [0] : X*P + WZ *Y (the crossings) In the 3rd slot he puts the numbers without zeros (the two last digits multiplication). That's his idea... and it is not based in separating the number into the 1st and the 2nd digit, but separating the last digit from the rest of your number. So let's go to your example: 127 x 23 = (12 x 2 ) [00] + (2 x 7 + 3 x 12) [0] + (3 x 7) now I will write the numbers in the slots , for that I'll use the bracket for the slots: [ 12 x 2 ] [ 2 x 7 + 3 x 12 ] [ 3 x 7 ] [24] [ 50 ] [21] Now the 3rd slot is larger than 10, so the 2 is going to be added to the middle slot: [24] [52] [1] The middle slot is larger than 10, so the 5 will be added to the 1st slot: [29][2][1] the answer is so: 2921

[@MF-ur2xu]

tivmego You could use his 3-digit trick and make 23 become 023.

[@MF-ur2xu]

or use the lattice multiplication trick.

[@nonhlanhlakhoza6288]

tivmego

[@LoganStargazer]

These math tricks are useful. Would you please do a series on *why* these work? That would make them easier to remember, I think. Do the math the long hard way first, then point out what your shortcuts are doing.

[@akhtersimasharmin6446]

Finallyyy i got the reallllll math teacher that actually helping students but not shouting at them for not doing correctly. School teachers should watch these vdo so that they could teach students this wayyyy...

[@bstandsforbuilding5567]

40% of the comments are wise guys trying to prove this method wrong because they don't know how to use it properly.

[@neetunagula1962]

ya u r right

[@goldennebula5013]

ikr

[@poojakumarijazbaatmere872]

the

[@poojakumarijazbaatmere872]

the yu y6

[@poojakumarijazbaatmere872]

6

[@meta4282]

To multiply 3 digits numbers this way Eg: 127 x 23 - use the exact method as in video, leaving out the (100 value) of 127, so work out firstly 27 x 23 = 621 then add your second number (23) with 00 on the end to this: 621 add 23(00) like below. 621 2300 (second number in equation gets 00 behind) ------please read on - it gets exciting!!! ---------- 2921 or 156 x 42 (drop the 1) = 56 x 42 = 2352 2352 4200 (second number in equation gets 00 behind) --------- 6552 If you are multiplying 256 x 42 256 x 42 (drop the 2) = 56 x 42 = 2352 2352 4200 (second number in equation gets 00 behind) 4200 (add this value twice for every hundred value in your equation) --------- 10752

[@neetunagula1962]

hmm not needed to write such a long comment just bla bla i just warn u not to give once morelike that

[@meta4282]

Neetu Nagula Long comments are needed to explain important things.

[@neetunagula1962]

😈🙅

[@mariafe7050]

Marachenka Ok great method So when I do 472 x 38, 72 x 38 = 2,736, now use 38 with 3,800, but do that 4 times Or either just multiply it = 15,200 Do adding so 2,736 + 15,200 = 17,736 Answer would be 17,736 Ok is is good but I saw the other video about that first

[@himanshiraikwar8053]

thanks marachenka it's a good method

[@SyedHannanZakir]

We cannot use the underscore all the times. For example if we get the multiplication of both first two and last two numbers greater than or equal to 10 (As in case of 64*36, we get 6*3=18 and 4*6=24), we will write just four digits not the underscore (1824 not 18_24). Also if the first number is less than 10 and second one is greater than or equal to 10 (As in case of 34*23, we get 3*2=6 and 4*3=12), we will write just three digits not the underscore (612 not 6_12). I suggest a few rules for the general equation: ab*cd (e.g; 31*21) First Step [Let (a*c and b*d) = A]: 1) Don't use underscore: i) if you get 4 digit number after first operation: "a*c>9 and b*d>9" (e.g for 64*36, 1824) ii) if you get first number less then 10 and second greater than equal to 10: "a*c

[@catwithaknife198]

Does it matter if AC is > or < 10?

[@catwithaknife198]

The last 2 calculations should be multiplyed by 10 before they are added.

[@catwithaknife198]

A= 1824 B= A10 A+B= 20064 =C What is C?

[@salumtummundi9462]

Just modify it bruh and u carry FIRST thing you carry U trying to look smart but you aint And mpdifiy it on your own if you don't like his

[@amernoori4157]

Why aren't there more people like you on Earth!

[@franciosmarchendie3218]

hey that trick is pretty good but do 97 times63 by this method....! i suggest use this method for checking either ur multiplication is right or not

[@superjojo555]

@@salumtummundi9462 9x6 = 54

[@salumtummundi9462]

@@superjojo555 oh yeah

[@chilaw51]

97*63 9*6= 54 7*3 =21 Therefore its 54_21 But we only write the One and keep the two to add it later on there fore it would be like so. 54_1 (The 2 in 21 , Since it's tens will add it later on) 9x3=27 7*6=42 27 + 42 = 69 So, 5 4 _ 1 2 6 9 Equal 6111

[@fastsciencecrafts]

So what happens when you pick numbers for witch the product of their last digits is greater than 10?

[@rakibhasan-hd9rc]

Was searching for this comment bruhh

[@yuvrajbhati4023]

BRO SOMEONE SAID IT DO 44 X 57

[@sonyaeames7047]

@@yuvrajbhati4023 4*5=20. 4*7=28. So that is 2028 add 4*7=28. 5*4=20. 28+20=48. So 2028+480=2508 not sure why you add 480 and not 48 but it works!

[@henry8558]

This is how teachers should had teach me in school 😭

[@elvisodell1376]

Hahahah

[@kaelyneades5789]

Facts

[@LesserMoffHootkins]

But they couldn’t, because they were ignorant

[@JohnDee633]

The problem is they come up with a certain way of showing work. And you’re forced to do it their way. It’s not about the correct answer, it’s about following rules. Then later in life you have to teach yourself to work smarter.

[@GhostMush-r4z]

THANK YOU SO MUCH! You don’t know how happy it made me when I was able to solve them so quickly! 😁

[@regonite1495]

"Big brain time"

[@naokimc]

"it's" BIG BRAIN time

[@zero0police]

or even quicker... instead of 43 x 21 simplify the equation. instead 43 x 20. 860 right? add the remainder 43 that you left out of the equation because you took away 1 from 21, and there you have it. 903

[@TehXyllo]

That works better with problems with a the ones digit under 5

[@diegomendez1771]

That works

[@alwaysq4191]

I calculated my timing Without method: 1 min With method : 10 sec

[@ajpaulson8831]

Qiqi Zhang great job!

[@dariustiu8470]

wut??

[@zo3651]

I LOVE THIS VIDEO. SO GLAD I FOUND YOUR CHANNEL!!!!!!!!!!!!!!!!

[@PolskiOlympia]

All the examples had a low number at The end 4[2] x 6[3] what about 78 x 67?

[@eduardocortez476]

Same process, except you carry over the tens place

[@TalentedTenth]

+Eduardo Cortez not sure what you mean when you say carry over the tens place?

[@Shawsh2143]

***** It works for every number combination from 0-100 m8.

[@SameeyaRanjan]

+Michal Chmielewski (PolskiOlympia) its simple : 78*67 = 5226 1. 7*6 = 42 2. 8*7 = 56 - 42_6 (5 from point 2 has been carried over to the tenth's place i.e below the blank space) 3. 7*7 = 49 4. 8*6 = 48 - 49+48 = 97 + 5 that was in the tenth's place = 102 Since 2 is at the unit's place so we place 2 in the blank, and now it becomes 4226 with 10 carried over to the hundred's and thousand's place as 1 and 0 were carried to the next adjacent numbers. Hence, 42+10 = 52 And your answer is 5226 :D

[@deana9826]

Sam Ranjan Cheers! This is what was missing from the video

[@markcabiles8226]

What if the product of the units are two digit? What u di u do?

[@robertushkatea214]

Carry the numbers over. Example 98x76 would be this: 9x7=63 8x6=48 So far we have 63__48 Now for the middle: 9x6 + 8x7 = 110 So we get 63|110|48 From 110, we carry 11 over 63, and from 48, we carry the 4 over 0: 11 4 63|0|48 63|0|8 Add the numbers that were carried: 74|4|8 So the answer is 7,448.

[@kekwnet]

@@robertushkatea214 please tell of 84by68

[@onlinecsk]

Thank you. Any shortcut for 3 digits * 2 digits

[@ThePiMan0903]

Thanks for these tricks tecmath!

[@evanclemons8658]

"I'll rub that out"

[@justinvelez5793]

I’m In 10 grade and I wacht this thanks bro I owe you one for getting me out of smart lunch

[@harassaeed6365]

this doesnt work with high 2 digit numbers like 99x97

[@Knowledgeovergrades]

Have you tried the box method for multiplication? I made a video on that.

[@happypamplona3793]

Exactly

[@larrymachon5771]

Yes i tried his examples multiples times, use the same trick as he used but one of them is workin

[@larrymachon5771]

None* yuh*

[@abhinav1690]

97*(100-1)

[@SuongThol]

I like your video, I am a teacher in Cambodia, I have some videos to share. Thank you for sharing this video. Good luck.

[@colonelbagz1113]

Very impressed and it burst some dead braincells back to life! thank you. I tried to be clever and did a 3 digit x 3 digit. got close but not right. Where do you put the dash if you do 3 numbers x 3 numbers?

[@kray97]

You're basically FOILing two binomials.

[@VijayKumar-pr9dn]

kray97

[@platniumking5913]

yeah

[@hyperslow1233]

kray97 Boy, that is 2 monomials, or one binomial.

[@trobin]

HyperSlow no it isn’t if you treat 21 as 20+1 and 31 as 30+1, which is essentially what he is doing, it is two binomials

[@1morejack]

what am i doing wrong with 56 x 17 =? can you do this one?

[@tecmath]

56 x 17 -> First and last digits respectively (5 x 1 =5) and (6 x 7 =42). We get 542 so far. Middle (tens) digits are 5 x 7 + 6 x 1 = 35 + 6 = 41. We have 542 41 Answer is 952

[@Metamoksha_]

i don't get it.. if i follow your trick on the vid, we're suppose to put blank between 5 and 42 which means 5_42 +41 = 9142

[@Birdo0o]

i think if the last one has to digits we dont put blank in the middle

[@sivadasank3602]

56 x 17=952

[@Arddy]

Ever so helpful you are =/. Tecmath showed the formula, remember not to put in a space if it's double digits

[@sonofkratos6]

Thank you for the video. I was doing this and realized that it is faster to do the equation backwards. Starting from the right side of the equation.

[@chrismendoza7024]

I want to learn about big digit in last ex. 59×38?

[@SWL6852]

59x38 (5x3=15) 15____ (9x8=72) 1572 (5x8+9x3)-> 40+27=67 Add~ 1572 _67_ 2242 59x38=2242

[@YuHeYeo]

Excuse me sensei. What am I adding. I get perplexed :(.. 1572+67?

[@YuHeYeo]

I am confused. I understand everything up until you say (add). What in specific am I adding please show in more detail sensei.

[@randomchannel503]

@sharon wang liu He added the 67 to the 57 part of 1572 then added the remainders

[@sisis608]

@@YuHeYeo 1572 , put 6 under 5 and 7 under 7 and then add, .. 7+7 gives 14, which is 4 with a carry 1, you take the carry 1 and put it with the 6 and the 5 , so it becomes 6+5+1=12, again that's 2 with a carry 1, which you add to the 1 at the begining, so from right to left , you get 7, 4, 2, and 2 or 2247 which is the answer

[@ik89_in96]

I already leard this when I was 10 and that this method does not always work for example :25 x 46 Because there is a 5 you will need a different method or tricj

[@GigaRxge]

You can I created a trick it always works After doing the steps it will come 11,230 Basically add 2 and 3 For example 35×46 It will come 15830 Add 8 and 3 its 11 and then add 1 to 15 its 16 and now remove the 3 from there and boom the ans is 1610

[@ik89_in96]

@@GigaRxge thx

[@GigaRxge]

@@ik89_in96 anytime friend

[@ik89_in96]

@@GigaRxgeI'm a girl

[@GigaRxge]

@@ik89_in96 oh

[@ahnafrahamanchoudhury]

you kmow this techer's voice is like avengers: thor

[@marcelliscrmnt]

My mind was totally blown! My dad would be proud.

[@Anuradha-cc1hh]

i love this guy

[@bartuakgun4206]

At the last one's i had the first one wrong

[@Vidurathegreat]

what about 49 x 61

[@abhinavpathak9922]

49*61= 4*6 then 9*1 then 9*6+4*1 in between carry over 5 which will be added to 24 and the answer is 2989

[@Vidurathegreat]

abhinav pathak thanx bro

[@ikennanaluchukwudavid1624]

I hope i am not too late but I just want to say that YOU ARE AMAZING FOR SHAING THIS Sir YOU EARNED A SUB

[@whatsappseries]

47 into 45 how many

[@mazharyosafzaiikhankarachi3734]

Hello [phone] Pakistan Karachi Whats App Nombr Mazhar

[@datcandlewak7521]

47 x 45 = 2,115

[@sultanuddinwahidi6150]

Xtreme Gaming how

[@ahuxley1567]

Xtreme Gaming thanks can you show working, I get diff ans.

[@jeffk2678]

You sounds like thor 😂

[@dndxdndx]

This doesn't work for a few numbers: 23 x 97: step 1: 18 _ 21 step 2: 14+27=41 result = 22121 You'd have to add the 1 to the 10s digit to get 3 and get the answer 2231 But the method above is not consistent with the following multiplication: 29x96: step 1: 18 _ 54 step 2: 12+81= 93 result: 2784 which is wrong doing it the the video's method is also wrong as you get 5 digits. The answer should be 2511 I'd appreciate it if anyone could provide a consistent method

[@arctyphon2023]

Okay, so when we find that the second bank of numbers is higher than the single digits we have to amend the rules a little to compensate. How we will do this is say that when the second bank equals a number higher then 9, we don't leave a space. So lets look at it like this: 23x97=? Step 1: 1821 (We wont leave a gap as the second "bank" of numbers is a double digit number) Step 2: 1821+ (as we didn't leave a gap, we will consider the 2 middle numbers the"gap" therefore we must add them) 41 This could also be expressed as 1821+ 0410 Result = 2331 29x96=? Step 1: 1854 (We wont leave a gap as the second "bank" of numbers is a double digit number) Step 2: 1854+ (as we didn't leave a gap, we will consider the 2 middle numbers the"gap" therefore we must add them) 93 This could also be expressed as 1854+ 0930 Result = 2784 You had the calculation correct in both of your initial workings. I'm not sure where 2511 in your second problem came from. I'm going to do another one just to prove that we can replace the numbers we already have with 0's and hopefully clarify the point a little So lets do: 57x 84=? Step 1: 4028 (We wont leave a gap as the second "bank" of numbers is a double digit number) Step 2: 4028+ (as we didn't leave a gap, we will consider the 2 middle numbers the"gap" therefore we must add them) 76 This could also be expressed as 4028+ 0760 Result = 4788 Hope that i have helped in some small way.

[@Adityabhanot]

Arc Typhon howz this 41 coming .. plz explain

[@raghavbyala3825]

2231 coz 18_ 21 +4 1 22 31

[@Adityabhanot]

U haven't explained from wat logic u got 4 1 .. 4 n 1 is added dt I know

[@KINKNMN]

the answer to 29x96=2784 so it does work aha

[@kaushalkashyap7832]

I am from INDIA. sir, i like your way of teaching .great technique....

[@jamesnagai2571]

he neva uses numbers like 27 where the second digit is more than 5

[@samm4510]

Still does work though

[@vivekpanchagnula9993]

Might confuse people with all the carries. Once you start practicing it, it's fine.