Let's roll up our sleeves and solve this. We have 338 and we're going to multiply it by 13, essentially adding 338 to itself 13 times.
Step 1: 0 + 338 = 338
Step 2: 338 + 338 = 676
Step 3: 676 + 338 = 1014
Step 4: 1014 + 338 = 1352
Step 5: 1352 + 338 = 1690
Step 6: 1690 + 338 = 2028
Step 7: 2028 + 338 = 2366
Step 8: 2366 + 338 = 2704
Step 9: 2704 + 338 = 3042
Step 10: 3042 + 338 = 3380
Step 11: 3380 + 338 = 3718
Step 12: 3718 + 338 = 4056
Step 13: 4056 + 338 = 4394

So, 338*13 = 4394