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

How to multiply 2 digit numbers numbers up to 100 - calculating the fast way!
Using this method you will be able to multiply any pair of two digit numbers with each other - faster than a calculator! Become a math genius in no time at all using vedic math!

To see how to multiply 2 and 3 digits using a variation of this trick follow this link: https://www.youtube.com/watch?v=lvnST...

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Closed Caption:

G'day and welcome to the TecMath channel.
In this video today we are looking at the fast
way of multiplying two
two digit numbers together....so let's go!
First of all we'll see if you can multiply
some numbers together
I'll give you a question which is
twenty-one
times
thirty one.
I'll give you six seconds to work that out.
Go!
So time's up.
So if you got the answer of 651
you did really really well
you got the right answer
If you were busily reaching for the calculator but
couldn't find it in time bad luck
but you shouldn't need a calculator, and
I'll show you how to work it out quickly
Don't get all despondant if you didn't work it out
I'll show you how to work these out
So to get the first number of our answer we
multiply the first
digits in our two numbers here, so
2 x 3
is six, and we have the first part of
our answer
We leave a blank space.
To get the last number of our answer
we multiply the last digits of our two numbers here
So 1 x 1 is 1.
To get the middle part of this number here there is
a bit of a trick. What we do
is multiply
this number and this number
and this number and this number
and we add the two answers together
so 1 x 2 is 2
1 x 3 is 3
we add 2 and 3 together
and get the answer
six hundred fifty one
Hey, pretty easy 'eh?
We'll have a look at another one
So, what about 43
times 21, a little bit
harder this time
See how you go.
Have you got the answer yet?
I'll start working through this one.
So again
4 x 2 is 8
We leave the blank space
1 x 3 = 3
Then what we do is go...
remember this....
1 x 4, and we add this to 3 x 2
so
1 x 4 is 4
3 x 2
is 6
We add these together
We get the answer of 10
Now this leads to a problem,
so this is a little trick for to understand
There is only one space here
We only have space to fit one digit
So the digit it puts in out of this ten
is the zero,
and for the one
We carry this across
And we add it on, so
The answer we end up getting
1 + 8 is
9
0
3...nine hundred and three.
Very good.
I think we can go through one more
I'll rub that out and
let's have a look one more question
I think this time I'll do it in a nice
purple colour
and I'll do the question here
42
times
63
I'm going all out, using different
colours today, getting excited
Too excited, I can't wait to get the
answer - let's work it out
First number 4 x6
Leave a space.
is 24.
Leave a space.
2 x 3 is 6
And then what we do
And I hope not to get this wrong.
I had to remake the video earlier
as I stuffed up this one
Occassionally
I get all excited and I make
mistakes too.
But for YouTube videos we don't make mistake.
We always get 100% correct
OK
OK
We multiply
These two guys together.
4 x 3 is 12
6 x 2 is 12
And 12 + 12 is 24.
We add 24 on, OK?
We put the 4 there and
2 there.
So what answer did we get?
Two thousan
six hundred
and forty six
Hey that's the right answer.
Pretty cool right?
So if you practice these
you will get really good at them and
really fast. Your teacher will be
utterly astounded about how good
you are. Everyone will think
your a genius alright?
I mean don't go too far - people
might stop talking to you
but hey -
you do this, you'll do
really well.
And yes you may make a few mistakes.
We all make them.
So finally I will leave you
with a few questions
I'll write them, get you to pause the video
and work through them, then I'll work through
the answers as quick as I can.
Here they are.
22
times 34
I mean 32
see how you go on that one
fifty-one times
sixty three
and 82
times
fifty-one
pause the video
Then I'll get back to you
A couple of seconds and we'll
go through these.
OK so hopefully you've worked
through those
and we'll go through the
answers right now.
OK so
2 x 3 is 6
We leave the blank space.
2 x 2 is 4 and then we add four
and six together
which is ten. We get the answer
704
The next one
5 x 6
is 30
Leave a space
1 x 3 is 3
and then we get
the number 3 x 5 is 15,
1 x 6 is
6
15 plus 6
is 21, so I'll put that in a different
colour so it fits
This will be a one, and
this will be a 2 so our answer is
three thousand
two hundred and thirteen
On to the last one
5 x 8
is forty
Leave a blank space
1 x 2 is 2
then we go 1 x 8 and we add that
to 10
8 plus 10
is 18 - we put the 8 there and
the one there.
So our answer is four
thousand
one hundred and eighty two
I hope you did well on those.
See you next time