Multiply Faster than You Learned in School!

These two ways of multiplying are much easier and faster than any way you ever learnt in school! What's more they are easy to remember - easier than the usual method!
But what do you think?
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[@242math]

excellent multiplication techniques, students can certainly make use of these

[@tecmath]

Thank you

[@robertcattermole4586]

They can

[@taram9880]

I was taught the cross multiplication strategy a few years ago in 5th or 6th grade, but I’ve never heard of the rainbow strategy. Coming from a student, I like using the cross-multiplication when I’m taking a test or doing homework since it helps me multiply quickly, but I feel like if I get enough practice, I’ll be able to memorize the rainbow strategy and do large multiplication quickly in my head! Thank you so much for teaching me!

[@wyattstevens8574]

They're effectively the same. Rainbow multiplication is just writing it in a single line.

[@vijayrawat09]

your videos never stop to astonish me.

[@tecmath]

Thanks Vijay.

[@AmbroseChan]

cross multiplication is my favourite method! Excellent video! Thank you for making math easier!

[@tecmath]

Thanks. Go the cross method.

[@momogoes3329]

Thank you always looking for fast math videos for competition.

[@cassandrarose11]

I'm sure you get told this a lot, but you're genius in your teaching methods. Thank you immensely. Learn something new every day. 😅

[@tecmath]

Thank you Cassandra.

[@stonkeng]

I was taught cross multiplication in school in the 1950s, seems normal to me. Love your channel keep them coming, thanks.

[@Waffle510]

Wow you are in your 70's :o

[@stonkeng]

@@Waffle510 not quite.

[@tecmath]

That is cool! Where was that?

[@stonkeng]

@@tecmath Falmouth in Cornwall UK. It would have been the late 1950s. We were lucky we had a brilliant Maths teacher who made it a lot of fun. I still enjoy mental arithmetic, the reason I follow your channel on KZbin.

[@Waffle510]

@@stonkeng how old are you?

[@customthings3368]

Definitely the cross multiplication Sir! Why on earth would they've not shown this way in school. Even keeps the interest cos of the simplicity! Great job as always 👏

[@SpaceWithSam]

Great method Josh!

[@fxeditor1138]

Fantastic method! I'm really looking forward to the rest of the series.

[@kimsassenberg9444]

Why was I never taught this method? I am actually enjoying learning this math. Thank you.

[@Gkuljian]

I don't know which I prefer, but I've been waiting a long time for this. Now I have to practice it for a while. Thanks!

[@leonpatrick5606]

I was taught the cross multiplication. Awesome explanation

[@mr.niceguy1706]

The way you have such a calming voice is really enjoyable to watch your videos and easier to learn with your tricks.

[@tecmath]

Thanks. I save my yelling during lessons for real life! (jokes... I never yell!).

[@GlennGoryl]

Excellent. Thank you.

[@eviljack13666]

Rainbow has the back tracking, messy, cross is clean as hell.

[@tecmath]

I like cross so much more!

[@redravenradios5036]

Hello sir, Thanks for all you do! I was wondering if you could do a act math prep video? It would help so much

[@Him.TheOneAndOnly]

Both these are pretty much the same method, one is horizontal and the other vertical, but I think the cross multiplication version is easier to keep track of.

[@tecmath]

Yep. You could see as the numbers were coming out the similarity!

[@Him.TheOneAndOnly]

@@tecmath I love your channel, you have helped me understand numbers in general way better, thank you.

[@nirajpatel191]

I agree with you

[@DiowE]

I prefer cross method of multiplication shown in the video because it solves problem from right to left and this prevents minute errors (like forgetting to add carrying number) and it also saves us from hassle of erasing and rewriting new answers (like you had to do in rainbow method). [DiowE]

[@tecmath]

You could do rainbow right to left.

[@tonybarfridge4369]

Cross multiplying can also be done left to right which I prefer

[@djlazer1]

They are basically the same method just written different. That means you can do the rainbow method backwards.

[@mohammedatteeqanwaraneducation]

Excellent upload 👌 👍 Thank you for sharing 😋 👌 😊 😀 👍

[@koolkabab]

this changed my life

[@MathsByManeesh96]

Amazing Tricks

[@mcstruble]

wonderful, thank you! I like the cross method best :)

[@user-zk1jr1is1m]

Thank you

[@kr__gaurav]

i like the cross multiplication. we can do 3, 4 or as many nos. as much we want, quickly! and one more thing, ur channel is really amazing!👌🏻

[@richardbyrd7047]

I like the cross multiply method best.

[@Psalm_23]

Can you make videos on calculus such as limits and differentiation and integration please

[@marcusscott9800]

I prefer the cross multiplication method. Great video, keep up the great work!

[@tecmath]

Thanks. Another vote for cross!

[@nathanc11]

You such a great teacher. Thank you for the videos. Keep them up!

[@tecmath]

Thanks!

[@latharavigopal8773]

Excellent. Hope children can understand

[@terriblechristiangamer9128]

Thanks for the vid. I might be an outlier but the rainbow method works for me.

[@terrylane1492]

In reality, they are both the same methods just expressed in different ways. Well done thank you!

[@doolzo7362]

i prefer the cross multiplication, i really really enjoyed the video thank you!!!

[@cityofgarlic4088]

Hello Josh, can you do a video on linear equations with integral coefficients please

[@242henderson5]

this is fast and easy, love it

[@Toothydeere]

thank you

[@armand4226]

very good !!!

[@bezaleltinokunda8805]

Thank you so much..

[@johnryder1713]

Happy Christmas Josh and my condolences to you and all teachers in your country on the poor children in Tasmania at such a hard time for this to happen

[@tecmath]

Thank you and Merry Christmas to you. What happened in Davenport is heartbreaking. Those parents, teachers and classmates must be devastated.

[@johnryder1713]

@@tecmath Certainly and Amen Josh

[@ecgaming222]

you're the goat tecmath

[@tecmath]

A goat. Not THE goat.

[@agilthoriq2461]

Thanks for vids , how about making a videos about roadmaps for learning mathematics ?

[@sandralemmerman4748]

Thank you thank you

[@ericj199]

Woah! I really liked the rainbow method

[@Muskan-sb7zj]

Thank you. You are my life savior in account

[@tecmath]

Thank you for watching.

[@travisdrakereyes9302]

thx alot

[@davidtran4920]

From what I can see both processes are using the technique (vertical and horizontal). The horizontal one at first seems messier because you have to erase/rework where there are carries in other parts of the calculation. But if you calculate from right to left as you do for the vertical ones, then less mess and essentially doing the same thing.

[@dorischoo]

For mental, rainbow flows better, but needs more memories to hold numbers in the head is a struggle.

[@pastorrich7436]

I like the second method as it’s basically what I learned in school but with a nice twist.

[@tecmath]

It can be extended also easily for any multiplication... kzbin.info/www/bejne/gpitZpWEfaeVepY

[@mesplin3]

I prefer the rainbow method. I feel it's better when you need to approximate products quickly. Rainbow method isnt how I do it my head though. I like using the grid method more when multiplying because it extends to 3 digit numbers easier.

[@MsTinglez]

I definitely prefer the cross method but it's great to have more than one option. 👍

[@eviljack13666]

The cross method totally!

[@sheenamzafar8124]

Today’s content was amazing.

[@kanagadurkadevi3000]

வாழ்த்துகள் ஐயா 🎉 பயனுள்ள பதிவு நன்றி

[@poeticprincee9750]

I cannot believe I just learned this! I prefer the cross multiply method!!

[@tecmath]

Good to hear! I agree!

[@DatBoi141]

Cross multiplication cuz it's easier and thank you for these videos

[@NollywoodLegends]

Excellent. Please what app you use?

[@jonhellerup9550]

Cross is definitely my favorite

[@richardbyrd7047]

I like the cross method too.

[@kazuamoua]

I love the Rainbow one

[@flec6021]

You're giving me knowledge, sadly i can't support financially and all I can do is like, subscribe and share your vid on my friends. Thank you so much. Keep on doing more. Love from Philippines

[@tecmath]

Thank you for your kind words.

[@flec6021]

God bless you good sir.

[@vm_c137]

Thank God I learnt English, so that I can learn new cool things like this!

[@secret3957]

first multiplication, method 2 is how we learned it in school in the Netherlands. So what is the "standard way" of multiplication for you? 10x31 + 2x31?

[@flexthegamer458]

You made a mistake on your caption,I think you meant "Multiplication methods that are faster than you learnt at school"

[@tecmath]

Thanks Flex. Fixed.

[@kiminseattle3476]

Cool!

[@julians7697]

I agree with the comment of Faith. Careful home training free from useless waste and a school system that has math teachers like Josh.

[@blessed7927]

I prefer the regular way because I get lost in the steps. But I do like the percents to numbers switch in your other video

[@arteagaboyzzz]

I multiply place values sideways. Ex. 12x31(12×30 or 12x3=36and bring your 0 back in. Then 12x1=12. Add 360 and 12= 372 For 43x52 (43×50 and 43x2. Add answers = 2150+ 86= 2236

[@UKMikey]

How about doing the three stages (100s, outside 10s, inside 10s, 1s) as four different rows and sticking an appropriate number of zeroes at the end? Then you can add up the four rows and won't have to rub anything out. Doing all the multiplication tasks first and then adding everything at the end also means you don't have to swap tasks hopefully leading to a slightly faster result. What do you think?

[@tecmath]

That is how I would think about it mentally. I find cross multiplication stops all the need for that.

[@junivanofdragonia]

2:45 I personally like both. Depending on how it is written on the paper, just so I don’t have to rewrite the problem.

[@aletaschulz1108]

I like the cross method.

[@mickel29]

Multiplying faster than a rabbit.😂 if you know you know

[@V4K4R14N]

"Multiplying faster than a rabbit..." I had to stop for a second 😂

[@mrman6436]

Can you do a reverse percentage video please?

[@comelysleeper646]

I like the cross method my teacher didn't liked it when I tried using a calculator on a very simple equation so I'm starting to learn stuff the first time again

[@ChessQuickies]

I like both of them: they are similar ways that don't require as much calculation.

[@tecmath]

The funny thing... the calculation is the same as standard long multiplication - except the addition is more compressed.

[@arnoldmweyola5700]

on 0:45 how do you know how many spaces to put down after multiplying the numbers in the front?

[@gm2407]

I prefer the way I did it. I multiplied the tens in the first number by the entire second number. Then I multiplied the units in the first number by the entire second number. Then added them together. 43×52= 40×52= 2,080 3x52=156 2080+156=2,236 For me it was easier to see as it is easy to multiply a two digit number by any of n2-n9 and add a 0 at the end. Then just multiply the remaining units with the other two digit number. Perhaps I am just more practiced. tens by tens plus tens by units plus units by tens plus units by units Left to right rather than backwards that they teach in school. But it is all the same thing. I just cut out the middle by doing tens by whole number plus units by whole number example 64 x 83= 60×83=4,980 4×83=332 4,980+332=5312 I just thought about it. This is how the operations would be complete to multiply using the mechanical Curta calculator. Or at least one of the methods.

[@wickedbird1538]

Really like this.. now I need to analyze this to see WHY it works. But that’s just because I want to maintain my NERD status. PS. I prefer cross method.

[@tecmath]

Thanks! I'll give you a hint. For all of these we have the hundreds digit (T x T), tens digit (T x U +U xT), units (UxU).

[@kamikaze8645]

in Holland, the right hand cross multiplication is taught from grade school :)

[@nirajpatel191]

Cross multiplying work's best for me

[@VM-yd6zq]

It helps break down what is happening when we multiply, but it seems too confusing for those beginning double digit multiplication.

[@robertcattermole4586]

U r awesome

[@samhoward8909]

Awesome techniques but I think cross multiplication method for me!

[@nevastaka]

I recommend for me that the rainbow multiplication is better for me

[@wyattstevens8574]

Cross multiplication (because the rainbow method really only seems to work easily with numbers less than 100)

[@mcintosh6214]

This is the first video that I've actually known the method before.

[@Peendee]

😭😭😭 I’ve learned more math from you than I did in the 12 years I spent in school.

[@Ladylace97]

Both are good but I like the rainbow

[@tecmath]

:)

[@dorischoo]

I agree

[@imposterk9768]

I was so surprised how easily he did it i went to check on a calculator the guy is never wrong

[@Iamboredddd]

Hello Josh!

[@markking1960]

Guess I’ll just stick with the old school method, but it’s cool for the younger minds!

[@mohrakhsaidi8568]

Cross one please 🙏

[@The_Aspirant-banker]

Agree

[@infinitepr0d1gy55]

Do these methods work with more than double digits?

[@tecmath]

They can be modified - especially the cross method. kzbin.info/www/bejne/gpitZpWEfaeVepY

[@R1ester]

This method is harder to me to do than what I'm used to

[@eugenebalster3850]

Seems to me that although the methods are good, not really that much easier than the older method you already know, plus you need to remember the different rules for each one. If my old method always works, do I need a new way?

[@yashjadhav8519]

For three or four digit numbers how do we do this?

[@tecmath]

Check this one out kzbin.info/www/bejne/gpitZpWEfaeVepY

[@Yusran-ns6uj]

Please give us tutorial for 3 digits multiplication

[@stadeler1]

👏🏻👏🏻👏🏻👏🏻