Alright, let's solve this math problem step by step. First, we have the number 626. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 21. So, we're going to take the number 626 and add it to itself 21 times.
Step 1: 0 + 626 = 626
Step 2: 626 + 626 = 1252
Step 3: 1252 + 626 = 1878
Step 4: 1878 + 626 = 2504
Step 5: 2504 + 626 = 3130
Step 6: 3130 + 626 = 3756
Step 7: 3756 + 626 = 4382
Step 8: 4382 + 626 = 5008
Step 9: 5008 + 626 = 5634
Step 10: 5634 + 626 = 6260
Step 11: 6260 + 626 = 6886
Step 12: 6886 + 626 = 7512
Step 13: 7512 + 626 = 8138
Step 14: 8138 + 626 = 8764
Step 15: 8764 + 626 = 9390
Step 16: 9390 + 626 = 10016
Step 17: 10016 + 626 = 10642
Step 18: 10642 + 626 = 11268
Step 19: 11268 + 626 = 11894
Step 20: 11894 + 626 = 12520
Step 21: 12520 + 626 = 13146

So, 626*21 = 13146