Without delay, let's solve this. We've got 57 and we will be multiplying it by 21, that is, adding 57 to itself 21 times.
Step 1: 0 + 57 = 57
Step 2: 57 + 57 = 114
Step 3: 114 + 57 = 171
Step 4: 171 + 57 = 228
Step 5: 228 + 57 = 285
Step 6: 285 + 57 = 342
Step 7: 342 + 57 = 399
Step 8: 399 + 57 = 456
Step 9: 456 + 57 = 513
Step 10: 513 + 57 = 570
Step 11: 570 + 57 = 627
Step 12: 627 + 57 = 684
Step 13: 684 + 57 = 741
Step 14: 741 + 57 = 798
Step 15: 798 + 57 = 855
Step 16: 855 + 57 = 912
Step 17: 912 + 57 = 969
Step 18: 969 + 57 = 1026
Step 19: 1026 + 57 = 1083
Step 20: 1083 + 57 = 1140
Step 21: 1140 + 57 = 1197

So, 57*21 = 1197