OK, let's work through this together. We're starting with 521 and we're going to multiply it by 4, which means we add 521 to itself 4 times.
Step 1: 0 + 521 = 521
Step 2: 521 + 521 = 1042
Step 3: 1042 + 521 = 1563
Step 4: 1563 + 521 = 2084

So, 521*4 = 2084