Sure thing! We've got 20 and we're gonna multiply it by 8. That's the same as adding 20 to itself 8 times.
Step 1: 0 + 20 = 20
Step 2: 20 + 20 = 40
Step 3: 40 + 20 = 60
Step 4: 60 + 20 = 80
Step 5: 80 + 20 = 100
Step 6: 100 + 20 = 120
Step 7: 120 + 20 = 140
Step 8: 140 + 20 = 160

So, 20*8 = 160