OK, let's crack this. We're given 255 and our task is to multiply it by 4. Essentially, we'll be adding 255 to itself 4 times.
Step 1: 0 + 255 = 255
Step 2: 255 + 255 = 510
Step 3: 510 + 255 = 765
Step 4: 765 + 255 = 1020

So, 255*4 = 1020