Alright, let's solve this math problem step by step. First, we have the number 966. 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 966 and add it to itself 21 times.
Step 1: 0 + 966 = 966
Step 2: 966 + 966 = 1932
Step 3: 1932 + 966 = 2898
Step 4: 2898 + 966 = 3864
Step 5: 3864 + 966 = 4830
Step 6: 4830 + 966 = 5796
Step 7: 5796 + 966 = 6762
Step 8: 6762 + 966 = 7728
Step 9: 7728 + 966 = 8694
Step 10: 8694 + 966 = 9660
Step 11: 9660 + 966 = 10626
Step 12: 10626 + 966 = 11592
Step 13: 11592 + 966 = 12558
Step 14: 12558 + 966 = 13524
Step 15: 13524 + 966 = 14490
Step 16: 14490 + 966 = 15456
Step 17: 15456 + 966 = 16422
Step 18: 16422 + 966 = 17388
Step 19: 17388 + 966 = 18354
Step 20: 18354 + 966 = 19320
Step 21: 19320 + 966 = 20286

So, 966*21 = 20286