Yeah same I can do the math but suck at remembering the numbers so I have to write them down or I will forget

@@Lia-iw1ds same and then i waste time repeating the whole process

@@Lia-iw1ds same

Lol ye same..

This is so true I was very fast at this a year ago but I never used it again and when it's time to use it again I was slow af

Jose A that's no the case at all, the reason is that some questions specifically want you to use a certain method and doing that will help build memory

🤦Teachers should encourage different types of learning and solving

This isn't only the case for American sch. system)) hi from Uzbekistan

No it's not, only you teacher is

And so the Indian system is too

Same I was good at math and I've started to slow down and drop

saaaaaaame!

Same lol I smoke too much weed hahaha

@@BobGnarly420 It's not the weed. It's your habits. Challenge yourself daily and lower electronic consumption. It's obliterating your attention span.

@@trevmora nah ye i kno tha just I cba tryna be relatable ini😂

same

I can't picture anything in my head??? How is that possible??

Same

@@boperez2841 I can't do it too 😂 some people are better at it tham the others

Kathrin Turner ... welp I guess I'm more STUPID

Kathrin Turner you should say to yourself that practice makes perfect.

You are right Kathrin turner

There are methods you can use to cement numbers into your memory. A good way is the mnemonic major system, which allows you to convert numbers to words. That way you can visualize them. For example, I might see 3021 as "Miss net", or a net with a pink bow on top (to show that it's a lady, or a "miss"). It's a silly image, but memorable. If I know the system well then I can convert it back to a number without difficulty.

Sometimes you can make other associations too. Like "31616", for example. I see 316 as the well-know bible verse "John 3:16", and then the 16 just repeats after that.

Splash Toons no

Splash Toons Never

i dont wanna concentrate. o.o

That cought me off guard XD

Best comment so far

Lol

Hahaha

It's 12:14 am en for me

*12:14 am too early for me who stays up all night just trying to do sums in his head😅

Tell me why my dumb self clicked the time thing

That's how I did it too

Wow that's actually really cool

Also 1616 x 4 16 x 4 = 64 Since there are two 16's you can just say 6464

Darth Geros I did the column multiplication but in my head

Darth Geros I really like your our method it is very cool

I add a zero and then divide by two lol that way I don’t ever have to deal with decimals

@@ellevasc i square it then multiply by 10 then find the square root then divid by two

@@Michael-st9ky add an 0 and divide it by 2

It only works if you get the remainder as zero after dividing the number by 2. For me, this works better, Divide by 2 and add a zero to your answer only if the remainder is zero. If it isn't, add a 5 to your answer before the decimals come in if that makes sense!

Ooh interesting thank you for that

Wow cool! Thanks!

Q

@@oofnoob5164 U GOT AN IQ MIND XD

@@anxerz8792 thanks ?

@@anxerz8792 im a cuber..if u dont know what cuber means u can search in google

@@anxerz8792 cubing made my muscle memory good

Ya that's not how you multiply by five, that's how you divide by five.

@@avraham4497 That's an oof from me

Am I the only one or does this look like gibberish to anyone else. What is the context of this?

I do it for the most part... i'm 14

@@psychopathinthemaking how to times numbers by 2, 3, 4, 5, 6 etc..

Yes you are right 😀

Yeah

Ahmed Adem same I got the 9 thousand part but not the rest

Lmao I didn’t even get a chance to work it out because he gave me the answer too fast

@@Amieee WWWOOOWWWWWWW!!!!1 IMPRESIVE

Ali Al-Rashid !!!!!!!!111

@@Amieee Do you know me ?

Math teachers are on a whole other level of pathetic

Quick matfs

Easy peasy my mother macaroni is cheesy lol😂🤣

wow i didn't know that XD

Army 💜💜

@Floofy shibe you cannot divide both the sides by zero Its like multiplying on both sides by infinity And you know my friend that infinity is not defined And also 0/0 is indeterminant

Rolls Up I am from 🇵🇰 too

Namra Diy yiur

I'm pakistani too😊

Teachers: did u cheat?

Because you need to show the work 😂😂

Same.

K463178 same

Same here. It gets harder with bigger numbers though... x * y where x and y are both larger than, say, 15 gets exponentially harder. Or rather, it requires exponentially better short-term memory for numbers. Which is exactly my problem...

same

same here and most people say its better to calculate from right to left^^

If you replace the multiplier 5 by 10 * 0.5, you can add a zero to multiply by 10, and then divide by 2 to multiply by 0.5. You can divide by 2 by grouping the dividend into even number groups and dividing individually, minding carry. Example 1: 5 * 21613 = 0.5 * (10 * 21613) = 0.5 * 216130 216_130 108_065 Above, instead of multiplying, we halve each group and combine the results to produce the answer: 108065 Example 2: 5 * 1933 = 0.5 * 19330 19_330 09_165 Here, for the sake of example, we have the odd number 19 to be divided by 2, the quotient being 9 with a remainder of 1: 2 * 9 = 18 19 - 18 = 1 You will never have a bigger remainder than 1 because we're dividing by 2 and every second number is even. In case we encounter odd dividends like this, we have to add the half of that remainder to the next number, which is the 1 in 330 / 2 = 165. This half is of course 5, which is 0.5 relative to the remainder (thousands), but 5.0 in the next position (hundreds). So 165 becomes 665: 19_330 09_165 09_665 5 * 1933 = 9665 Don't forget zeros when you construct the final answer. Example: 5 * 1262017253801896 = 0.5 * 12620172538018960 12620172538018960 12_620_172_538_018_960 06_310_086_269_009_480 ^ ^ ^ 5 * 1262017253801896 = 6310086269009480

jl7986 Samee

That's how I was taught in 4th grade

+jl7986 That comes with practice. I like to split up or chunk the numbers in my head, by putting in commas just like I would on paper. I would look at 21613 x 5 as 21,613 x 5, and I'd work from left to right because that's how I read. 21 x 5 is 105 and 613 x 5 is 3065. But I've got to carry the "3" to the thousands place immediately to the left of the comma. I'd "see" the number as105,(3)065. I keep the three separate in parentheses so I automatically know to carry it to the left. 105,(3)065 = (105+3),065 = 108,065. This is known as "melding" numbers, and is covered in Ronald Doerfler's book, "Dead Reckoning: Calculating Without Instruments".

@@avraham4497 bruh

Thry do in middle school 4 me in 2020

Schools are just waste of time..

that's adorable!

Crazy to think that you’re nearly an adult now

@@dolgid839 17?

@@yourmomm yeah

@@dolgid839 59 more days! This comment took me back thanks! :)

I have a sharp memory when it comes to math and science and programming and grammar and stuff involving learning but when people ask me unimportant stuff I don't remember at all.

@@justfyox6869 i have a sharp memory when it comes to rubik's cube

that is an insane thing for teachers to say. i was taught that being able to do it mentally is fundamental to learning it correctly.

Sweet! Go Hawaii!

Paul Huggett yes, the 12 turns 13

You have a couple of carries in that problem.

^consuming**

This method helps me keep track of both the digit placement and decimal placement, I’m not sure why tho

😂

Separate by the digits, multiply and connect them back

+Victoria Medeiros what grade are u in and what are your grades like?

+Laolu why should I tell ypu

Victoria Medeiros I was just wondering, jeez, don't get so defensive, if you don't want to tell me u don't have to.

+Laolu Arogundade calm down wow!

Victoria Medeiros Are u fricking kidding me? I should calm down? Alright, whatever u say

😂😂😂😂😂😂😂😂😂😂

My Australian Ant Colony same

im 7 and this helped a lot

Now you are thirteen.

Skipper you will fall asleep

Skipper same

You're right ;-;

I'd be happy to be your teacher

ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ

its not a friend. its a bully. lol no jk. its really tough though. o.o

***** it is

Pause the vedio and calculate it in your head stupid

@@a.shirzad that was posted 5 years ago lol

@@pyrodemon131 you were still able to pause 5 years ago

Rhonda Ja Idk what you mean

Haha good for you doing math on break! 🤗

Math isn't boring but rather presented in a boring way in our shitty schools

2x10 is the same as 10x2...

21*361 Separate the digits. 2|1 multiply by each and combine again. 361*20 is 7220 +361 7581 361*21=7581

Adeeb Mahmud yea your right?🤔

Ex. 3492*38 ---> 3492(30+8) --- distributive property ---> 3492(30)+3492(8). It's more unwieldy to store separate values in your head and then proceed to add them, though.

Adeeb Mahmud hi

Adeeb Mahmud ok so basically you do the exact same thing except do it however many digits over again and add zeroes to each consecutive number you come up with and then add them all in your head

He has made another video clarifying your question ;)

Same

Same here

yea...its even harder and slower

same

nicolegend wow

you just need to know ur time tableles like me im 9 and i know mine till 100

karim786owais Hey Karim, Thanks for the reply little man! It's a pretty cool thing if you know math, seems you have it going pretty well :). I'm not into math that much, It seemed pretty cool to me to learn a new may of math. Curiosity really. What I'm more interested in is that children should learn on how to write English in a way that everybody could fully understand. In a respectful way, even. Ugh, what the heck, just don't tell me what to do kid. Typed for nothing..

I think it's better to keep track of the trailing zeros the whole way, so as not to get confused. With 626 x 7, when you multiply 6 x 7 for the first digit, you really are multiplying 600 x 7. So you drop the two zeros, multiply 6 x 7, and add the two zeros back on to the end of the number. Now you have 4,200. Then multiply the middle digit (2) x 7, which is really 20 x 7, due to the "2" being in the tens column. Drop the zero and add it back on at the end of the multiplication. 2 x 7 = 14, and add the zero back. You get 140. Add 140 to the original 4,200, by adding from left to right. 4,200 + 100 is 4,300, + 40 is 4,340. Then add the final 6 x 7: there are no zeroes to drop. You have 42. 4,340 + 40 = 4,380 + 2 = 4,382.

Joss Cues You are right, but that's assuming you know off the top of your head that 16x4 is 64 (if you don't, you then have to pre multiple 16x4 in your head (while you are still thinking about the first part of the equation) and then get the answer to 16x4 = 64 while remembering the next part of the equation) (and you have to remember that number for the rest of the equation) and then you have to remember the next 3 equations you wrote out, this method works for EVERY SINGLE NUMBER you don't have to know anything except your basic multiplication (12x12), and the next number you are looking at.

Make the first digit of 16 greater than 3 less than 10 and you have to carry

lol no, your way is harder than his.

Muhammad Saad

It takes almost no time if you practice.

not that hard

thєn juѕt prαctícє :/ єvєn thσ ítѕ 3 чєαrѕ єαrlíєr