Question

Multiply the following numbers by formula Nikhilam:
(i) $6\times 7$
(ii) $8\times 9$

Answer 1

(i)

$1$. Both numbers are of base $10$.

$2$. $6$ is $4$ less than $10$ and $7$ is $3$ less than $10$.

$3$. $\left(-4\right)\times \left(-3\right)=12$ (since base is $10$ we take $2$ and $1$ to the following).

$4$. $6-3$ OR $7-4=3$ (we add $1$ to $3$ we get $4$)

$5$. FINAL ANSWER=42.

(ii)

$1$. Both numbers are of base $10$.

$2$. $8$ is $2$ less than $10$ and $9$ is $1$ less than $10$.

$3$. $\left(-2\right)\times \left(-1\right)=2$

$4$. $8-1$ OR $9-2=3$

$5$. FINAL ANSWER=$72$.