Let's get this math done. We have 942 and we're going to multiply it by 15. This is the same as taking 942 and adding it to itself 15 times.
Step 1: 0 + 942 = 942
Step 2: 942 + 942 = 1884
Step 3: 1884 + 942 = 2826
Step 4: 2826 + 942 = 3768
Step 5: 3768 + 942 = 4710
Step 6: 4710 + 942 = 5652
Step 7: 5652 + 942 = 6594
Step 8: 6594 + 942 = 7536
Step 9: 7536 + 942 = 8478
Step 10: 8478 + 942 = 9420
Step 11: 9420 + 942 = 10362
Step 12: 10362 + 942 = 11304
Step 13: 11304 + 942 = 12246
Step 14: 12246 + 942 = 13188
Step 15: 13188 + 942 = 14130

So, 942*15 = 14130