Let's roll up our sleeves and solve this. We have 8 and we're going to multiply it by 9, essentially adding 8 to itself 9 times.
Step 1: 0 + 8 = 8
Step 2: 8 + 8 = 16
Step 3: 16 + 8 = 24
Step 4: 24 + 8 = 32
Step 5: 32 + 8 = 40
Step 6: 40 + 8 = 48
Step 7: 48 + 8 = 56
Step 8: 56 + 8 = 64
Step 9: 64 + 8 = 72

So, 8*9 = 72