Without delay, let's solve this. We've got 13 and we will be multiplying it by 6, that is, adding 13 to itself 6 times.
Step 1: 0 + 13 = 13
Step 2: 13 + 13 = 26
Step 3: 26 + 13 = 39
Step 4: 39 + 13 = 52
Step 5: 52 + 13 = 65
Step 6: 65 + 13 = 78

So, 13*6 = 78