OK, let's work through this together. We're starting with 49 and we're going to multiply it by 15, which means we add 49 to itself 15 times.
Step 1: 0 + 49 = 49
Step 2: 49 + 49 = 98
Step 3: 98 + 49 = 147
Step 4: 147 + 49 = 196
Step 5: 196 + 49 = 245
Step 6: 245 + 49 = 294
Step 7: 294 + 49 = 343
Step 8: 343 + 49 = 392
Step 9: 392 + 49 = 441
Step 10: 441 + 49 = 490
Step 11: 490 + 49 = 539
Step 12: 539 + 49 = 588
Step 13: 588 + 49 = 637
Step 14: 637 + 49 = 686
Step 15: 686 + 49 = 735

So, 49*15 = 735