Without delay, let's solve this. We've got 558 and we will be multiplying it by 20, that is, adding 558 to itself 20 times.
Step 1: 0 + 558 = 558
Step 2: 558 + 558 = 1116
Step 3: 1116 + 558 = 1674
Step 4: 1674 + 558 = 2232
Step 5: 2232 + 558 = 2790
Step 6: 2790 + 558 = 3348
Step 7: 3348 + 558 = 3906
Step 8: 3906 + 558 = 4464
Step 9: 4464 + 558 = 5022
Step 10: 5022 + 558 = 5580
Step 11: 5580 + 558 = 6138
Step 12: 6138 + 558 = 6696
Step 13: 6696 + 558 = 7254
Step 14: 7254 + 558 = 7812
Step 15: 7812 + 558 = 8370
Step 16: 8370 + 558 = 8928
Step 17: 8928 + 558 = 9486
Step 18: 9486 + 558 = 10044
Step 19: 10044 + 558 = 10602
Step 20: 10602 + 558 = 11160

So, 558*20 = 11160