Alright, let's solve this math problem step by step. First, we have the number 673. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 31. So, we're going to take the number 673 and add it to itself 31 times.
Step 1: 0 + 673 = 673
Step 2: 673 + 673 = 1346
Step 3: 1346 + 673 = 2019
Step 4: 2019 + 673 = 2692
Step 5: 2692 + 673 = 3365
Step 6: 3365 + 673 = 4038
Step 7: 4038 + 673 = 4711
Step 8: 4711 + 673 = 5384
Step 9: 5384 + 673 = 6057
Step 10: 6057 + 673 = 6730
Step 11: 6730 + 673 = 7403
Step 12: 7403 + 673 = 8076
Step 13: 8076 + 673 = 8749
Step 14: 8749 + 673 = 9422
Step 15: 9422 + 673 = 10095
Step 16: 10095 + 673 = 10768
Step 17: 10768 + 673 = 11441
Step 18: 11441 + 673 = 12114
Step 19: 12114 + 673 = 12787
Step 20: 12787 + 673 = 13460
Step 21: 13460 + 673 = 14133
Step 22: 14133 + 673 = 14806
Step 23: 14806 + 673 = 15479
Step 24: 15479 + 673 = 16152
Step 25: 16152 + 673 = 16825
Step 26: 16825 + 673 = 17498
Step 27: 17498 + 673 = 18171
Step 28: 18171 + 673 = 18844
Step 29: 18844 + 673 = 19517
Step 30: 19517 + 673 = 20190
Step 31: 20190 + 673 = 20863

So, 673*31 = 20863