 # 63^9 mentally calculated!

Tried some powers today and finally got one right! 63 to the 9th power!
Calculating it takes so long, I made 2 phonecalls during my calculation xD

3 Likes

nice

How did you do it? That seems so crazy haha

I literally calculated 63x63x63x63x63x63x63x63x63.

It was difficult. The hardest part is not the calculation but the seperation of numbers and remembering which number belongs where.

So when I was at 63^8, which is 248,155,780,267,521, I almost made a mistake by calculating 248,155,780,639,167x60.
639,167 is the last 6 digits of 63^7!
I knew something was off. I had to quickly go back, check the answers of 63^2 all the way to 63^7, realized that I almost messed up and then continue on.

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Very nice. Your mental calculations are impressive.

I’m just curious. Have you considered to square 63 with cross-multiplication, which gives 3969, then square 3969 again in the same way (or alternatively as (4000-31)^2), then square the result a third time to get 63^8? Seems faster and easier to me in order to obtain 248,155,780,267,521.

Just my two cents 1 Like

Thanks! I don’t use cross-method. I am testing the limits of my natural memory in the hardest way possible, the regular method we are all taught as children. This way I can show the extent of my abilities.

I prefer to calculate 63x63x63x63x63x63x63x63x63 over (((63^2)^2)^2)x63. The reason is because the jumps between the numbers is less. I find it easier to multiply 1 large number with a small number, for example 3938980639167x63. It’s easier than 15,752,961^2.

Calculating 15,752,961x15,752,961 is really hard if you don’t use the cross-method or abacus method and the chances for mistakes are higher. I can do it but it takes much longer because I have to keep a lot more zero’s in mind.

15,752,961x15,000,000 = 236294415000000

3938980639167x60= 236338838350020

See the difference in zero’s?

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i personally prefer to transfer the zero to a sense of space.
In this way you could spend less source for trivial zeros.