Alright, let's solve this math problem step by step. First, we have the number 518. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 42. So, we're going to take the number 518 and add it to itself 42 times.
Step 1: 0 + 518 = 518
Step 2: 518 + 518 = 1036
Step 3: 1036 + 518 = 1554
Step 4: 1554 + 518 = 2072
Step 5: 2072 + 518 = 2590
Step 6: 2590 + 518 = 3108
Step 7: 3108 + 518 = 3626
Step 8: 3626 + 518 = 4144
Step 9: 4144 + 518 = 4662
Step 10: 4662 + 518 = 5180
Step 11: 5180 + 518 = 5698
Step 12: 5698 + 518 = 6216
Step 13: 6216 + 518 = 6734
Step 14: 6734 + 518 = 7252
Step 15: 7252 + 518 = 7770
Step 16: 7770 + 518 = 8288
Step 17: 8288 + 518 = 8806
Step 18: 8806 + 518 = 9324
Step 19: 9324 + 518 = 9842
Step 20: 9842 + 518 = 10360
Step 21: 10360 + 518 = 10878
Step 22: 10878 + 518 = 11396
Step 23: 11396 + 518 = 11914
Step 24: 11914 + 518 = 12432
Step 25: 12432 + 518 = 12950
Step 26: 12950 + 518 = 13468
Step 27: 13468 + 518 = 13986
Step 28: 13986 + 518 = 14504
Step 29: 14504 + 518 = 15022
Step 30: 15022 + 518 = 15540
Step 31: 15540 + 518 = 16058
Step 32: 16058 + 518 = 16576
Step 33: 16576 + 518 = 17094
Step 34: 17094 + 518 = 17612
Step 35: 17612 + 518 = 18130
Step 36: 18130 + 518 = 18648
Step 37: 18648 + 518 = 19166
Step 38: 19166 + 518 = 19684
Step 39: 19684 + 518 = 20202
Step 40: 20202 + 518 = 20720
Step 41: 20720 + 518 = 21238
Step 42: 21238 + 518 = 21756

So, 518*42 = 21756