Without delay, let's solve this. We've got 477 and we will be multiplying it by 21, that is, adding 477 to itself 21 times.
Step 1: 0 + 477 = 477
Step 2: 477 + 477 = 954
Step 3: 954 + 477 = 1431
Step 4: 1431 + 477 = 1908
Step 5: 1908 + 477 = 2385
Step 6: 2385 + 477 = 2862
Step 7: 2862 + 477 = 3339
Step 8: 3339 + 477 = 3816
Step 9: 3816 + 477 = 4293
Step 10: 4293 + 477 = 4770
Step 11: 4770 + 477 = 5247
Step 12: 5247 + 477 = 5724
Step 13: 5724 + 477 = 6201
Step 14: 6201 + 477 = 6678
Step 15: 6678 + 477 = 7155
Step 16: 7155 + 477 = 7632
Step 17: 7632 + 477 = 8109
Step 18: 8109 + 477 = 8586
Step 19: 8586 + 477 = 9063
Step 20: 9063 + 477 = 9540
Step 21: 9540 + 477 = 10017

So, 477*21 = 10017