Sure thing! We've got 558 and we're gonna multiply it by 15. That's the same as adding 558 to itself 15 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

So, 558*15 = 8370