7/120 + 1/48 = ? How to Add The Fractions and Find The LCD - BASIC MATH!

[@winnepeterson6570]

I’m 74 and did it in about 10 seconds. Some things you just never forget. Thank you!

[@billstevens8553]

Me too, at 77!

[@machman261063]

I took the long way to arrive at 19/240. (1) multiply both denominators 120 x 48 = 5760 (2) multiply each numerator (a) 7 x 48 = 336 (b) 1 x 120 = 120 (3) restate the equation as 336/5760 + 120/5760 = 456/5760 (4) to find LCD divide answer by 4 = 114/1440 (5) then divide answer by 2 = 57/720 (6) then divide answer by 3 = 19/240.

[@NoxiousRob]

I did it pretty much the same way, albeit took a step more than you as instead of dividing 456/570 by 4, I divided it by 2 twice. If I'd worked out that both 456 and 5760 were divisible by 8 I could have skipped straight to 19/240, but then again, it's probably easier to just keep halving the numbers than try to work out if they divide by more than 2. Once I got to 57/720 I knew I couldn't divide by 2 again, but also knew that both numbers divided by 3, giving 19/240 and as 19 is a prime number I knew I couldn't simplify it any further.

[@panlomito]

I send this sum to a friend and he came with a very nice solution: the denominators can be divided by 12 so 1/12 . 7/10 + 1/12 . 1/4 = 1/12 . (14/20 + 5/20) = 1/12 . 19/20 = 19/240 Nice !

[@panlomito]

But then again he never heared about LCD...

[@btpcmsag]

The words used for this are, By factoring (not "dividing") the denominators as greatest common fractions, 1/12 is found. Because these two denominators, 120 & 48 can also be factored (not "divided") by 2, 3, 4, 6, and 8, but 12 is better because it's the biggest. By using 1/12 like this, you won't need to REDUCE your final answer, as it will all ready be in lowest terms. Thank you for this observation! I think it helps to thoroughly understand the topic of fractions addition! John should USE it!!! 😊

[@btpcmsag]

If we used 1/8 instead of 1/12, it would still give the right answer! 1/8(7/15) + 1/8(1/6) = 1/8(14/30 + 5/30) = 1/8 × 19/30 = 19/240 ✓ Or if we used 1/6: 1/6(7/20) + 1/6(1/8) = 1/6(14/40 + 5/40) = 1/6(19/40) = 19/240 ✓ Or if we used 1/4: 1/4(7/30) + 1/4(1/12) = 1/4(14/60 + 5/60) = 1/4(19/60) = 19/240 ✓ Or if we used 1/2: 1/2(7/60) + 1/2(1/24) = 1/2(14/120 + 5/120) = 1/2(19/120) = 19/240 ✓ It just takes more step when you use a fraction larger than 1/12.

[@panlomito]

@@btpcmsag Which solution do you like most?

[@myrasummers5767]

Lowest common denominator is 240. 14/240 +5/240 = 19/240.

[@pw1889]

19/240 - reasoning...find a number to multiply by 8 that results in a zero...that would be 5 x 8 = 40, so 5 x 48 = 240. That just happens to be 2 times 120, so 14/240 + 5/240 = 19/240

[@jald910]

Me too

[@The_Aussie_Enquirer]

That’s how I did it too

[@damirzeric1018]

You can always multiple each dominator by the other dominator . Won't necessarily be the LCD but always works and them just simplify afterwards.

[@SaveAllTheWolves]

It’s sad that calculators have ruined things for many kids actually learning how to do things. I had a professor back in the early 1980s who used to say, “don’t be a slave to your calculator.” He taught me to always try to come up with a realistic range of what answer to expect using common sense before using my calculator. I’ve seen you do the same.😊 your students are blessed to have you

[@btpcmsag]

At 12:40 John omits the key reason for 2^4 in the LCD but not 2^3, which is that 2^3 is all ready represented by 2^4 (it is a factor of 2^4) and therefore does not have to be represented again.

[@IreneDuncan-l5b]

You make it far more complicated than necessary. I did it in my head in a few seconds.

[@dazartingstall6680]

I did it in my head in 0.25 seconds while dancing the fox-trot in a wet-suit... Half an hour before the video was uploaded. Just thought I'd mention that, since it seems to be the done thing to brag about such matters. Sheesh!

[@Sw-nv4hw]

You get an elephant stamp but your missing the point of these videos . So clever solve the worlds problems too😅

[@dazartingstall6680]

@@Sw-nv4hw I think you missed the point of my comment.

[@Sw-nv4hw]

You may be right i may be crazy. My dad was a gun at math me well.. i was dreaming of butterflies and rainbows. He was long winded and my concentration span was about one minute. Thank you this is important sorry if i got you wrong.😊

[@Metheglyn]

There is nothing wrong with people being proud of being able to solve these kinds of problems. One of the points of the videos is to let people try their hand at math that might seem daunting to some. And anything with fractions in it is daunting to some. I agree with you that some comments along the lines of "this is far too easy! Did it in my head in 5 seconds" are annoying, since they tend to discourage people for whom the problems aren't easy. On the other hand, TabletClass Math tend to make long-winded videos, which _is_ a help to many in his intended audience, but frustrating to others. As such critique is not necessarily completely unwarranted.

[@barbarahuff117]

Like your content. Good for the brain. Thanks

[@napoleonlaguerre5587]

Math is one of my Favor class when I was in HAITI

[@panlomito]

120 = 10 . 12 = 5 . (2 . 3 . 2 . 2) and 48 = 4 . 12 = 2 . (2 . 3 . 2 . 2) so the LCD = 120 . 2 = 240 So 14/240 + 5/240 = 19/240

[@tomtke7351]

Is a PIA but adding two fractions requires a COMMON.(=same) denominator. 7/120 + 1/48 120=10×12 48=4×12 10=2×5 4=2×2 the common denominator is 12×2×2×5 = 240 so 240/240× {7/120 + 1/48) =(2×7)/240 +(5×1)/240 =14/240 + 5/240 =19/240

[@STEAMerBear]

I did it in my head, but it’s at my limits as I struggled to remember, compare & eliminate the common prime factors of 120 & 48! Once I figured out they have an LCD of 240, life got simple.😊

[@gavindeane3670]

I know he's talking about the LCD here, but if you're doing it in your head remember that you don't need to find the LCD. Any convenient common denominator will do, and then you can simply the resulting fraction at the end.

[@Like_An_Eagle]

When adding fractions, the first step is to make sure they have the same denominator. To do this, you multiply each fraction by 1 in a way that keeps the fraction’s value the same but changes the denominator. For example, we’ll multiply the first fraction, 7/120, by 48/48, and the second fraction, 1/48, by 120/120. This gives both fractions a common denominator of 5760. So, 7/120 becomes 336/5760, and 1/48 becomes 120/5760. Now that they have the same denominator, we can add the two numerators. This gives us 456/5760. Finally, we simplify 456/5760 by dividing both the top and bottom by 24 (their greatest common divisor), which gives us the final answer simplified as 19/240. --- Math Breakdown: 1. Original problem: (7/120) + (1/48) 2. Multiplying to get a common denominator: (7/120) * (48/48) + (1/48) * (120/120) 3. New fractions: (336/5760) + (120/5760) 4. Adding the fractions: (336/5760) + (120/5760) = (456/5760) 5. Simplified result: (456/5760) ÷ 24 simplifies to (19/240)

[@Like_An_Eagle]

I love me some good ol' fraction math LOL

[@Like_An_Eagle]

Which also simplifies to 0.07916666666666666.... 😅

[@panlomito]

The problem here is the huge numbers if you choose to bowtie the fractions. I will always first simplify fractions and then use the LCD to avoid these huge numbers.

[@Like_An_Eagle]

@@panlomito could you explain the bowtie method?

[@dazartingstall6680]

@@Like_An_Eagle a c ad + bc ---- + --- = ------------ b d bd

[@pumaspaw]

I did it in my head with 28/480+10/480......38/480.....19/240

[@DavidRobinson-rj2sp]

Good refresher.

[@dazartingstall6680]

7/120 + 1/48 LCD: 2⁴ × 3 × 5 = 240 14/240 + 5/240 =19/240

[@debasismajumdar8634]

Extremely simple oral maths. 7/120=7/(24×5) & 1/48=1/(24×2) Next (7x2)/(24×5×2) & (1×5)/(24×2×5) Finally (14+5)/240=19/240 In less than 15 seconds. 😅

[@1234larry1]

if you had 2^2, 3^2, wouldn't you ignore a 2 or 3 on either side, since 2 is 2^1 and 3 is 3^1?

[@daisybuttercup6801]

I worked that out in my head. All you need is a common denominator which is 240

[@johng.1703]

120/8=15 15*48=720 6*120=720 so we have 42 over 720 added to 15 over 720 = 57 over 720 = 19 over 240

[@delladog]

Jezz did it in my head, the LCD had to be a factor of 120 and divisible by 48, so either120, 240, 360 basic maths says 48 goes into 240 five times so 240 is the LCD, the rest is easy.

[@Cutestar6757]

Cooll also 1/24{7/5+1/2}=1/24{14+5/10}=19/240..

[@에스피-z2g]

7/120+1/48= 14/240+5/240= 19/240

[@bonnie115]

That seems a very convoluted way of finding the LCD... and not even necessary to easily solve this.

[@pbanik]

Try to find the lowest common denominator and that simplifies it. 7/120 = 14/240 1/48= 5/240 14/240+5/240= 19/240

[@niranjanchakraborty1139]

Ans=7/120 +1/48. LC M=240 now. 7×2/240+1×5/249=19/240.

[@joebizzarro2054]

I know it's supposedly a faux pas to mix decimals and fractions, but I do all the time to solve these things in my head. I see a 120 and a 48 and I immediately think "12". So, 1/48 becomes 0.25/12, which then becomes 2.5 / 120. This gives you 7+2.5 / 120 = 9.5 / 120. Now you fix the faux pas, by doubling both numerator & denominator, and, voila, 19/240.

[@nirprizant4228]

exactly

[@raya.pawley3563]

Thank you

[@chadwagoner7056]

Why is the exponent used as a full expression rather than the other numbers that are prime?

[@petesmith9472]

You went up..I went down to six x 20 then six x six 48.

[@johnoehrle5973]

How can you expect us to watch a long video to check our 19/240 answer we got in under 5 seconds?

[@gavindeane3670]

You don't need to watch the whole video if you just want to check your answer. He always states the answer at the start, before he goes into the explanation.

[@nirprizant4228]

i calculated in my head in 30 second that 48 x2.5 is 120 end from there in 5 seconds more that 19/240 is the answer

[@Stylux-z1p]

10/15/2024 9:19 PM Find the LCD of 120 & 48 [PRIME FACTORIZATION] 120 -> [2] x 60 -> [2] x 30 -> [2] x 15 -> [3] x [5] , 120 = 2 x 2 x 2 x 3 x 5 = 2³ x 3 x 5 48 -> [2] x 24 -> [2] x 12 -> [2] x 6 -> [2] x [3] , 48 = 2 x 2 x 2 x 2 x 3 = 2⁴ x 3 prime factors with the highest power(exponent) of the two numbers : 2⁴ x 5 x 3 = 16 x 5 = 240 LCD Adjust numerators for common denominator: For the first term : 240 / 120 * 7 = 14 For the second term : 240 / 48 * 1 = 5 [14 / 240] + [5 / 240] = [19 / 240] ---> ANS

[@russelllomando8460]

got 19/240 LCD is 240 it's 120 X 2 and 48 X 5 thanks for the fun.

[@Metheglyn]

The obviously superior solution: 7 1 0,7 1/4 0,7 + 0,25 0,95 9,5 19 ------- + ----- = ------- + --------- = ----------------- = ----------- = --------- = --------- 120 48 12 12 12 12 120 240 The 'obviously superior' was meant sarcastically.

[@robertpickell3984]

19 OVER 240.... I'M 90 YEARS OLD AND DID IT IN MY HEAD. JUST HAD TO FIND A COMMON DENOMINATOR WHICH WAS 240/

[@williamthurl2607]

Get the denominator the same for both number they both go

[@lorettalindsey8575]

21

[@leetucker9938]

19/240 . 19 is prime so can't cancel down anymore

[@HeavenMoses-l5f]

19 over 240

[@ramesankd1604]

Okay

[@jessemallory741]

19/240 it suddenly dawned on me 240 was the LCD

[@josephlaura7387]

19/240

[@johnmarchington3146]

My answer is 19/240

[@rebeccaweil1]

I have forgotten this math LCD

[@deebaker988]

1/15

[@Metheglyn]

How did you get that?

[@safirahmed]

Numbers like to get away on vacation from time to time.

[@dwaipayandattaroy9801]

176/ 5760

[@Metheglyn]

120*48 = 5760; 7*48+1*120 = 456; 456/5760 = (19*24) / (240*24)= 19/240 I cant see how you got 176. But you should generally shorten fractions as much as possible when writing solutions to math problems, which would have made your answer 11/360 (when reducing by 16)

[@dwaipayandattaroy9801]

@Metheglyn it's 48+7 = 55+ 120+1= 176, and not 48*7 + 120*1 = 456 okay 💀😂✌

[@johanvanzyl8479]

Much quicker to see this is 0,95 / 12. x 20/20 Voila!

[@charleshodge6202]

keep it simple....0.079!

[@sambhardwaj68]

1/20

[@mauriziograndi1750]

The cleverest way to do things is to express yourself with the least possible words or numbers. So if you go through the comments you’ll see who is the ones.

[@dazartingstall6680]

Fewest.

[@Metheglyn]

@@dazartingstall6680 The point of this is not to demonstrate cleverness. It is to teach and learn. If more words (or numbers) gets your point clearer across, then that is preferable.

[@dazartingstall6680]

@@Metheglyn I was joking. In this case the joke revolved around irony. The irony lies in the fact that, while talking about cleverness in self-expression, the speaker had used the technically inaccurate "least" instead of the technically correct "fewest." Some extra irony is added by this error occurring in a mathematical setting, since the difference between the two is in regard to whether the noun denotes things which are countable or non-countable. I stress (this being the internet where everything turns into an argument) that my comment was no more than a light-hearted dig.

[@Metheglyn]

@@dazartingstall6680 Yeah, sorry; My comment was directed towards @mauriziograndi1750. I don't know how I got you put on as recipient.

[@charlesmclaughlin3578]

14/240 + 5/240…. Not sure how this happened

[@chrisdissanayake6979]

7 1 -- + -- 120 48 Finding the Least Common Denominator of 120 and 48 : 24 x 5 x 2= 240 7 14 -- = -- 120 240 1 5 -- = --- 48 240 14 5 -- + -- 240 240 19 --- 240

[@Hewhowalks-fv5mq]

At least you addmit to your mistakes😡

[@luna_belle5029]

admit*

[@panlomito]

@@luna_belle5029 Adding to his admission.

[@UnderAttack-x1s]

Admit has one "d". Do you admit to your mistakes?

[@panlomito]

@@UnderAttack-x1s This is not a mistake for a math teacher. The A of PEMDAS: addmit!

[@romanwondimu8696]

21

[@gordion1]

Things have moved on I thought the lowest common denominator was the way to go.

[@Metheglyn]

LCD is a fine tool to solve this. It is not the only way, but if your answer is a properly reduced fraction, you will find the LCD anyway.

[@danmike2305]

👍

[@najeebullahhaleem6679]

❤❤

[@SA-bx9cp]

Sorry but you made a meal of that, enough to put people off, there was an easy 2 minute solution to this

[@J.Inez4589]

You made more complicated and going to fast. Made me confused.

[@btpcmsag]

It confuses me when John uses too many extra words , like um, and so then, okay, in other words, and so on and so forth. When he says "over here, this, and over there that," I have no idea what he's pointing at, since the tiny DOT his pen makes is too small to show up on my screen. I have to REPLAY that part two or three times, keeping in mind all the possible combinations of places he could be referring to.

[@gonzaloromero8717]

You have to be more careful on the structure and content of your videos. I suggest you have a didactic video script and follow it. I find that you insert unnecessary content that distract the learner.

[@jiyoungpark6233]

1/10...😊

[@Metheglyn]

How do you get that?

[@jiyoungpark6233]

@@Metheglyn 7/120 + 5/120 = 12/120 = 1/10...

[@mikechappell4156]

48x2.5=120, (1x2.5+7)/120=9.5/120, (9.5/120)*(2/2)=19/240. Showing the prime factorization of both denominators was fun, but if I didn't understand the point of doing it, I might have been lost. Sometimes your material is interesting, but you babble a lot.

[@Vieweratlarge]

Hated it!😕

[@gopherspace8571]

👍👏🙏💪😎🌎

[@sekharb6651]

19/240

[@JamesSutton-ip2oi]

19/240

[@mossesmadjemite2289]

19/240

[@эльдар-в4п]

19 / 240

[@CorazonYago]

19/240

[@lindagillian8157]

19/240

[@trevaperes5343]

19/240