OK, let's crack this. We're given 880 and our task is to multiply it by 13. Essentially, we'll be adding 880 to itself 13 times.
Step 1: 0 + 880 = 880
Step 2: 880 + 880 = 1760
Step 3: 1760 + 880 = 2640
Step 4: 2640 + 880 = 3520
Step 5: 3520 + 880 = 4400
Step 6: 4400 + 880 = 5280
Step 7: 5280 + 880 = 6160
Step 8: 6160 + 880 = 7040
Step 9: 7040 + 880 = 7920
Step 10: 7920 + 880 = 8800
Step 11: 8800 + 880 = 9680
Step 12: 9680 + 880 = 10560
Step 13: 10560 + 880 = 11440

So, 880*13 = 11440