Sure thing! We've got 854 and we're gonna multiply it by 15. That's the same as adding 854 to itself 15 times.
Step 1: 0 + 854 = 854
Step 2: 854 + 854 = 1708
Step 3: 1708 + 854 = 2562
Step 4: 2562 + 854 = 3416
Step 5: 3416 + 854 = 4270
Step 6: 4270 + 854 = 5124
Step 7: 5124 + 854 = 5978
Step 8: 5978 + 854 = 6832
Step 9: 6832 + 854 = 7686
Step 10: 7686 + 854 = 8540
Step 11: 8540 + 854 = 9394
Step 12: 9394 + 854 = 10248
Step 13: 10248 + 854 = 11102
Step 14: 11102 + 854 = 11956
Step 15: 11956 + 854 = 12810

So, 854*15 = 12810