Let's roll up our sleeves and solve this. We have 957 and we're going to multiply it by 13, essentially adding 957 to itself 13 times.
Step 1: 0 + 957 = 957
Step 2: 957 + 957 = 1914
Step 3: 1914 + 957 = 2871
Step 4: 2871 + 957 = 3828
Step 5: 3828 + 957 = 4785
Step 6: 4785 + 957 = 5742
Step 7: 5742 + 957 = 6699
Step 8: 6699 + 957 = 7656
Step 9: 7656 + 957 = 8613
Step 10: 8613 + 957 = 9570
Step 11: 9570 + 957 = 10527
Step 12: 10527 + 957 = 11484
Step 13: 11484 + 957 = 12441

So, 957*13 = 12441