Without delay, let's solve this. We've got 624 and we will be multiplying it by 23, that is, adding 624 to itself 23 times.
Step 1: 0 + 624 = 624
Step 2: 624 + 624 = 1248
Step 3: 1248 + 624 = 1872
Step 4: 1872 + 624 = 2496
Step 5: 2496 + 624 = 3120
Step 6: 3120 + 624 = 3744
Step 7: 3744 + 624 = 4368
Step 8: 4368 + 624 = 4992
Step 9: 4992 + 624 = 5616
Step 10: 5616 + 624 = 6240
Step 11: 6240 + 624 = 6864
Step 12: 6864 + 624 = 7488
Step 13: 7488 + 624 = 8112
Step 14: 8112 + 624 = 8736
Step 15: 8736 + 624 = 9360
Step 16: 9360 + 624 = 9984
Step 17: 9984 + 624 = 10608
Step 18: 10608 + 624 = 11232
Step 19: 11232 + 624 = 11856
Step 20: 11856 + 624 = 12480
Step 21: 12480 + 624 = 13104
Step 22: 13104 + 624 = 13728
Step 23: 13728 + 624 = 14352

So, 624*23 = 14352