Question

How would we multiply the number 13680347,35702369 and 25692359 with 9 mentally? what is the pattern that emerges

Answer 1

Its as simple as you think..
let us consider a number as 13680347

1st - Multiply the no. by 10 we get 136803470 or simply add 0( zero) in ones place.

2nd - Substract the number by origibal number.

example -
136803470-13680347= 123123123

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 :

The trick we apply to find the multiple is by writing 9 as (10-1).

So,

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

Like wise,

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

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

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