Without delay, let's solve this. We've got 51 and we will be multiplying it by 23, that is, adding 51 to itself 23 times.
Step 1: 0 + 51 = 51
Step 2: 51 + 51 = 102
Step 3: 102 + 51 = 153
Step 4: 153 + 51 = 204
Step 5: 204 + 51 = 255
Step 6: 255 + 51 = 306
Step 7: 306 + 51 = 357
Step 8: 357 + 51 = 408
Step 9: 408 + 51 = 459
Step 10: 459 + 51 = 510
Step 11: 510 + 51 = 561
Step 12: 561 + 51 = 612
Step 13: 612 + 51 = 663
Step 14: 663 + 51 = 714
Step 15: 714 + 51 = 765
Step 16: 765 + 51 = 816
Step 17: 816 + 51 = 867
Step 18: 867 + 51 = 918
Step 19: 918 + 51 = 969
Step 20: 969 + 51 = 1020
Step 21: 1020 + 51 = 1071
Step 22: 1071 + 51 = 1122
Step 23: 1122 + 51 = 1173

So, 51*23 = 1173