OK, let's crack this. We're given 521 and our task is to multiply it by 23. Essentially, we'll be adding 521 to itself 23 times.
Step 1: 0 + 521 = 521
Step 2: 521 + 521 = 1042
Step 3: 1042 + 521 = 1563
Step 4: 1563 + 521 = 2084
Step 5: 2084 + 521 = 2605
Step 6: 2605 + 521 = 3126
Step 7: 3126 + 521 = 3647
Step 8: 3647 + 521 = 4168
Step 9: 4168 + 521 = 4689
Step 10: 4689 + 521 = 5210
Step 11: 5210 + 521 = 5731
Step 12: 5731 + 521 = 6252
Step 13: 6252 + 521 = 6773
Step 14: 6773 + 521 = 7294
Step 15: 7294 + 521 = 7815
Step 16: 7815 + 521 = 8336
Step 17: 8336 + 521 = 8857
Step 18: 8857 + 521 = 9378
Step 19: 9378 + 521 = 9899
Step 20: 9899 + 521 = 10420
Step 21: 10420 + 521 = 10941
Step 22: 10941 + 521 = 11462
Step 23: 11462 + 521 = 11983

So, 521*23 = 11983