Sure thing! We've got 800 and we're gonna multiply it by 5. That's the same as adding 800 to itself 5 times.
Step 1: 0 + 800 = 800
Step 2: 800 + 800 = 1600
Step 3: 1600 + 800 = 2400
Step 4: 2400 + 800 = 3200
Step 5: 3200 + 800 = 4000

So, 800*5 = 4000