OK, let's work through this together. We're starting with 660 and we're going to multiply it by 3, which means we add 660 to itself 3 times.
Step 1: 0 + 660 = 660
Step 2: 660 + 660 = 1320
Step 3: 1320 + 660 = 1980

So, 660*3 = 1980