Question

How would we multiply the numbers 13680347, 35702369 and 25692359 with 9
mentally? What is the pattern that emerges.

Answer 1

first you'll multiply first number with 9 then second and then third then add the answers

Answer 2

Answer and Explanation:

To find : How would we multiply the number 13680347,35702369 and 25692359 with 9 mentally? What is the pattern that emerges?

Solution :

To find the multiple of given numbers by 9 is writing 9 as (10-1).

So,

$13680347\times9=13680347\times (10-1)= 136803470-13680347=123123123$

$35702369\times9=35702369\times(10-1)=357023690-35702369=321321321$

$25692359\times9=25692359\times(10-1)=256923590-25692359=231231231$

The pattern that emerges is last three digits 1,2 and 3 repeat in a cyclic pattern.