OK, let's work through this together. We're starting with 972 and we're going to multiply it by 15, which means we add 972 to itself 15 times.
Step 1: 0 + 972 = 972
Step 2: 972 + 972 = 1944
Step 3: 1944 + 972 = 2916
Step 4: 2916 + 972 = 3888
Step 5: 3888 + 972 = 4860
Step 6: 4860 + 972 = 5832
Step 7: 5832 + 972 = 6804
Step 8: 6804 + 972 = 7776
Step 9: 7776 + 972 = 8748
Step 10: 8748 + 972 = 9720
Step 11: 9720 + 972 = 10692
Step 12: 10692 + 972 = 11664
Step 13: 11664 + 972 = 12636
Step 14: 12636 + 972 = 13608
Step 15: 13608 + 972 = 14580

So, 972*15 = 14580