MENTAL MATH IN 49 SECONDS 😎 #shorts

Mental math in 49 seconds #shorts

This is a test to see if YouTube shorts are any good at bringing my channel views/subs.

[Prxsh_]

This is how I do it:

27x10 = 270
270+27 = 297

IT'S RAPID

[WsgPeopleee]

297, and I feel like a master just for learning this

[scmtuk]

You can actually see how this works, using algebra:
A 2-digit number can be represented by the expression 10a+b
If we then multiply this number by 11 we get 11(10a+b) = 110a+11b
We can then split the coefficients of a and b into sums of powers of 10, so 110a+11b = 100a+10a+10b+b
If we then factor, we get 100a+10(a+b)+b
Therefore, the 100s digit is simply the same as the original 10s digit.
The units digit remains the same, and the 10s digit is the sum of both digits.

What about if we have a 3 digit number, i.e. 100a + 10b + c
If we multiply this by 11 we get 1100a + 110b + 11c
Again, if we split the coefficients into sums of powers of 10 we get:
1000a+100a+100b+10b+10c+c
If we then factor out the common coefficients, we get:
1000a+(100a+b)+(10b+c)+c

Therefore, for a 3 digit number, the first and last digit as usual are the same.
Then the 2nd digit in the product is the sum of the 1st and 2nd digit in the original number
The 3rd digit in the product is the sum of the 2nd and 3rd digit in the original number

Infact, you can repeat this process for any number.
The first digit is always the first digit, and the last digit is always the last digit, and then every other digit in the middle is the sum of consecutive pairs of digits.

Take this large number for example. 176936 x 11.
The first digit is 1, and the last digit is 6, i.e.
Then we simply sum pairs of consecutive digits.
3 + 6 = 9
9 + 3 = 12 -> 2
6 + 9 = 15 + 1 = 16 -> 6
7 + 6 = 13 + 1 = 14 -> 4
1 + 7 = 8 + 1 = 9

Therefore 176936 x 11 = 1926496

However, you don't really _need_ algebra at all to see how it works, it just looks interesting (to some people).
If you just simply remember that 11 = 10 + 1, then it's pretty obvious.
If you take a number such as 176936, then multiply it by 11, you're just adding itself to 10 times itself, which is:
1769360
+176936

Therefore, it's pretty obvious to see how you sum pairs of consecutive numbers.

[LudusYT]

Trying YouTube Shorts out to see if this can help bring in more people to the channel. We’ll see 🤷🏽‍♂️

[jtris]

Here's a quick algebraic explanation:

10a + b represents a two digit number, with 10a being the tens digit and b being the units digit.
11(10a + b)
= 110a + 11b
= 100a + 10a + 10b + b
= 100a + 10(a + b) + b

[icedo]

For the brave among you, this trick also has a working pattern for at least three digit numbers as well. Lets take 11 x 123. The the first number and the last number stay the same (1__3), but to get the second number you add the first and the second numbers together (1+2=3, -> 13_3), and to get the third you add the second and the third numbers together (2+3=5, -> 1353), and indeed 11 x 123 = 1353. Carrying would apply the same here and probably would have to work right to left to be rigorous. I suspect this works for numbers of other lengths as well, but I've never had the balls to try and go for it yet.

[saltyflowers]

i used this in my math class today and my teacher said i used a calculator. 🤔😂

[abigailkimani]

same i feel like im a pro at multiplication

[shahdmansour]

THANK YOUUUU
that was pretty helpfull

[ItsMeRema]

Thanks for the trick! I feel like I’m smart!

[levijohnson]

This method seems much simpler than I did it, I would just do (27 x 10) + (27 x 1) this is usually how I break apart harder problems mentally.

[HavingSexWhileHigh]

how to do this but with 3 digit numbers:

let's say we're doing 527*11
First, you put the numbers like this: 52 7
Then add 52 and 7
You get 59
Put 9 between 52 and 7
You get 5297
now you have a 5
Add the five to the hundreds, in this case it is 2
You get 7
so boom, you get 5797

[Dreamtobesucced]

Sir mera kal regional level he. Aur aapne mujhe ye video deke mete sare doubt clear kar diye thanku so muchh❤

[framemaxxer]

just found this channel recently with them integral shits, great content

[BlossomedJewelsOfficial]

I used this trick and I stumped my whole family and class lol

[Creative_Canvases]

297 is the answer for the last question.
And thanks for the trick

[LoveZeinabe]

I got excited and didn't even finish the video and went to ask my mom to quiz me she said 11×78 I said 7, 158 we've been laughing for 5 minutes.💀

[destinyfaith]

Wowww I love this, I’m going to teach my students this! They’re gonna love it, thank u

[starlord]

Every body here be like 297😭😭😭that's not what I came up with

[RandomEG]

If 3x - y = 12, what is the value of 8^x/2^y?

A: 2^12
B: 4^12
C: 2^14
D: 6