OK, let's work through this together. We're starting with 507 and we're going to multiply it by 4, which means we add 507 to itself 4 times.
Step 1: 0 + 507 = 507
Step 2: 507 + 507 = 1014
Step 3: 1014 + 507 = 1521
Step 4: 1521 + 507 = 2028

So, 507*4 = 2028