OK, let's crack this. We're given 255 and our task is to multiply it by 12. Essentially, we'll be adding 255 to itself 12 times.
Step 1: 0 + 255 = 255
Step 2: 255 + 255 = 510
Step 3: 510 + 255 = 765
Step 4: 765 + 255 = 1020
Step 5: 1020 + 255 = 1275
Step 6: 1275 + 255 = 1530
Step 7: 1530 + 255 = 1785
Step 8: 1785 + 255 = 2040
Step 9: 2040 + 255 = 2295
Step 10: 2295 + 255 = 2550
Step 11: 2550 + 255 = 2805
Step 12: 2805 + 255 = 3060

So, 255*12 = 3060