Let's get this math done. We have 66 and we're going to multiply it by 10. This is the same as taking 66 and adding it to itself 10 times.
Step 1: 0 + 66 = 66
Step 2: 66 + 66 = 132
Step 3: 132 + 66 = 198
Step 4: 198 + 66 = 264
Step 5: 264 + 66 = 330
Step 6: 330 + 66 = 396
Step 7: 396 + 66 = 462
Step 8: 462 + 66 = 528
Step 9: 528 + 66 = 594
Step 10: 594 + 66 = 660

So, 66*10 = 660