Question

Using standard identity, solve:
1010×990 = _________ $\left[3Marks\right]$

Answer 1

$1010$ and $990$ can be written as $(1000+10)$
and $(1000-10)$ respectively.$\left[1Mark\right]$

$1010\times 990=(1000+10)(1000-10$
$[\text{We know,}{a}^2-b^2=(a+b\left)\right(a-b\left)\right]$$\left[1Mark\right]$
$={1000}^2-{10}^2$
$=1000000-100$
$=999900$$\left[1Mark\right]$