how to calculate multiplication of 10 digit no. mentally?

Question

how to calculate multiplication of 10 digits or more by mind and not by calculator or computers or by physically?

Answer 1

learn vedic mathematics....

Answer 2

I do it by visualizing the way I do it with a pencil and paper. However, as I get older, I sometimes forget the "carry" number in the final step - the addition of columns. So, normally do the process twice. If the second answer doesn't agree with the first, I do it a third time. The best 2 of 3 is what I usually settle for.
You can't imagine how much paper (and batteries) I save on.

Answer 3

well first for tens you just add a zero

by larger numbers like by 12

you multiply by 10 first like if you have 12*13

so you have you multiply 13*10 and get 130 now multiply by 2 and 26 then add the numbers together


so you have 130+26=156

if you have like 32*25 you multiply the number by 30 (since you work with the first number - the ones digit) so you have 25*30 or just multiply by 3 and add a zero when you're done you get 75 then 750 then you multiply the number the ones digit which is 2 and get 50

now add 750+50=800

and do all the steps i said above if you have1234567890*12 you just multiply 12*1000000000 then by 200000000 and so one for every number and when you get the numbers add them together

i hope you understood that because it makes sense to me but that's also because i wrote it if now e-mail me check ya later ♥

Answer 4

by phisically....? anyway not my job to correct your english.....join an abacus class ive heard it helps...but maybe not a 10 digit no. and also it depends what your multiplyin it with.

Answer 5

hmm its so hard i think theres no easier way