OK, let's crack this. We're given 802 and our task is to multiply it by 15. Essentially, we'll be adding 802 to itself 15 times.
Step 1: 0 + 802 = 802
Step 2: 802 + 802 = 1604
Step 3: 1604 + 802 = 2406
Step 4: 2406 + 802 = 3208
Step 5: 3208 + 802 = 4010
Step 6: 4010 + 802 = 4812
Step 7: 4812 + 802 = 5614
Step 8: 5614 + 802 = 6416
Step 9: 6416 + 802 = 7218
Step 10: 7218 + 802 = 8020
Step 11: 8020 + 802 = 8822
Step 12: 8822 + 802 = 9624
Step 13: 9624 + 802 = 10426
Step 14: 10426 + 802 = 11228
Step 15: 11228 + 802 = 12030

So, 802*15 = 12030