Sure thing! We've got 521 and we're gonna multiply it by 10. That's the same as adding 521 to itself 10 times.
Step 1: 0 + 521 = 521
Step 2: 521 + 521 = 1042
Step 3: 1042 + 521 = 1563
Step 4: 1563 + 521 = 2084
Step 5: 2084 + 521 = 2605
Step 6: 2605 + 521 = 3126
Step 7: 3126 + 521 = 3647
Step 8: 3647 + 521 = 4168
Step 9: 4168 + 521 = 4689
Step 10: 4689 + 521 = 5210

So, 521*10 = 5210