Question

The solution of the following by using suitable identities:
$204\times 206$ is -------

Answer 1

The given product $204\times 206$ can be rewritten as $(200+4)\times (200+6)$ and we solve it as follows:

$(200+4)(200+6)=200(200+6)+4(200+6)=(200\times 200)+(200\times 6)+(4\times 200)+(4\times 6)=40000+1200+800+24=42024$

Hence, $204\times 206=42024$.