Alright, let's solve this math problem step by step. First, we have the number 389. 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 389 and add it to itself 21 times.
Step 1: 0 + 389 = 389
Step 2: 389 + 389 = 778
Step 3: 778 + 389 = 1167
Step 4: 1167 + 389 = 1556
Step 5: 1556 + 389 = 1945
Step 6: 1945 + 389 = 2334
Step 7: 2334 + 389 = 2723
Step 8: 2723 + 389 = 3112
Step 9: 3112 + 389 = 3501
Step 10: 3501 + 389 = 3890
Step 11: 3890 + 389 = 4279
Step 12: 4279 + 389 = 4668
Step 13: 4668 + 389 = 5057
Step 14: 5057 + 389 = 5446
Step 15: 5446 + 389 = 5835
Step 16: 5835 + 389 = 6224
Step 17: 6224 + 389 = 6613
Step 18: 6613 + 389 = 7002
Step 19: 7002 + 389 = 7391
Step 20: 7391 + 389 = 7780
Step 21: 7780 + 389 = 8169

So, 389*21 = 8169