Question

Simplify using the properties of the whole number.

$999\times 9999$

Answer 1

Simplifying using the properties of the whole number

$999\times 9999$$=999\times (10,000-1)$ $\because 9999=10,000-1$

$=999\times 10000-999\times 1$ $\because a(b-c)=a\times b-a\times c$

$=99,90,000-999$

$=99,89,001$

Hence, $999\times 9999=$ $99,89,001$