OK, let's work through this together. We're starting with 637 and we're going to multiply it by 48, which means we add 637 to itself 48 times.
Step 1: 0 + 637 = 637
Step 2: 637 + 637 = 1274
Step 3: 1274 + 637 = 1911
Step 4: 1911 + 637 = 2548
Step 5: 2548 + 637 = 3185
Step 6: 3185 + 637 = 3822
Step 7: 3822 + 637 = 4459
Step 8: 4459 + 637 = 5096
Step 9: 5096 + 637 = 5733
Step 10: 5733 + 637 = 6370
Step 11: 6370 + 637 = 7007
Step 12: 7007 + 637 = 7644
Step 13: 7644 + 637 = 8281
Step 14: 8281 + 637 = 8918
Step 15: 8918 + 637 = 9555
Step 16: 9555 + 637 = 10192
Step 17: 10192 + 637 = 10829
Step 18: 10829 + 637 = 11466
Step 19: 11466 + 637 = 12103
Step 20: 12103 + 637 = 12740
Step 21: 12740 + 637 = 13377
Step 22: 13377 + 637 = 14014
Step 23: 14014 + 637 = 14651
Step 24: 14651 + 637 = 15288
Step 25: 15288 + 637 = 15925
Step 26: 15925 + 637 = 16562
Step 27: 16562 + 637 = 17199
Step 28: 17199 + 637 = 17836
Step 29: 17836 + 637 = 18473
Step 30: 18473 + 637 = 19110
Step 31: 19110 + 637 = 19747
Step 32: 19747 + 637 = 20384
Step 33: 20384 + 637 = 21021
Step 34: 21021 + 637 = 21658
Step 35: 21658 + 637 = 22295
Step 36: 22295 + 637 = 22932
Step 37: 22932 + 637 = 23569
Step 38: 23569 + 637 = 24206
Step 39: 24206 + 637 = 24843
Step 40: 24843 + 637 = 25480
Step 41: 25480 + 637 = 26117
Step 42: 26117 + 637 = 26754
Step 43: 26754 + 637 = 27391
Step 44: 27391 + 637 = 28028
Step 45: 28028 + 637 = 28665
Step 46: 28665 + 637 = 29302
Step 47: 29302 + 637 = 29939
Step 48: 29939 + 637 = 30576

So, 637*48 = 30576