Question

What is another strategy that you can use to multiply 2 digit by 2 digit numbers?

Answer 1

You may write them separating the units and tens digits, and then use FOIL to add 4 easy tems. For example, let's compute $21\cdot 36$:

$21\cdot 36=(20+1)(30+6)=600+120+30+6 = 756$