Let's get this math done. We have 282 and we're going to multiply it by 21. This is the same as taking 282 and adding it to itself 21 times.
Step 1: 0 + 282 = 282
Step 2: 282 + 282 = 564
Step 3: 564 + 282 = 846
Step 4: 846 + 282 = 1128
Step 5: 1128 + 282 = 1410
Step 6: 1410 + 282 = 1692
Step 7: 1692 + 282 = 1974
Step 8: 1974 + 282 = 2256
Step 9: 2256 + 282 = 2538
Step 10: 2538 + 282 = 2820
Step 11: 2820 + 282 = 3102
Step 12: 3102 + 282 = 3384
Step 13: 3384 + 282 = 3666
Step 14: 3666 + 282 = 3948
Step 15: 3948 + 282 = 4230
Step 16: 4230 + 282 = 4512
Step 17: 4512 + 282 = 4794
Step 18: 4794 + 282 = 5076
Step 19: 5076 + 282 = 5358
Step 20: 5358 + 282 = 5640
Step 21: 5640 + 282 = 5922

So, 282*21 = 5922