Multiplication methods

1. Multiplication by distributive law:
i. a * (b + c) = a * b + a * c
ii. a * (b - c) = a * b - a * c

2. Multiplication by \begin{aligned}5^n\end{aligned}:
When need to multiply with 5 power n , then we can
put n zeros to the right of multiplicand and divide the number so formed by\begin{aligned}2^n\end{aligned}

Example: 576 * 625
\begin{aligned}
= 576 * 5^4 \\
= \frac{5760000}{2^4}\\
= \frac{5760000}{16}\\
= 360000
\end{aligned}