Let's get this math done. We have 812 and we're going to multiply it by 13. This is the same as taking 812 and adding it to itself 13 times.
Step 1: 0 + 812 = 812
Step 2: 812 + 812 = 1624
Step 3: 1624 + 812 = 2436
Step 4: 2436 + 812 = 3248
Step 5: 3248 + 812 = 4060
Step 6: 4060 + 812 = 4872
Step 7: 4872 + 812 = 5684
Step 8: 5684 + 812 = 6496
Step 9: 6496 + 812 = 7308
Step 10: 7308 + 812 = 8120
Step 11: 8120 + 812 = 8932
Step 12: 8932 + 812 = 9744
Step 13: 9744 + 812 = 10556

So, 812*13 = 10556