Alright, let's solve this math problem step by step. First, we have the number 4. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 20. So, we're going to take the number 4 and add it to itself 20 times.
Step 1: 0 + 4 = 4
Step 2: 4 + 4 = 8
Step 3: 8 + 4 = 12
Step 4: 12 + 4 = 16
Step 5: 16 + 4 = 20
Step 6: 20 + 4 = 24
Step 7: 24 + 4 = 28
Step 8: 28 + 4 = 32
Step 9: 32 + 4 = 36
Step 10: 36 + 4 = 40
Step 11: 40 + 4 = 44
Step 12: 44 + 4 = 48
Step 13: 48 + 4 = 52
Step 14: 52 + 4 = 56
Step 15: 56 + 4 = 60
Step 16: 60 + 4 = 64
Step 17: 64 + 4 = 68
Step 18: 68 + 4 = 72
Step 19: 72 + 4 = 76
Step 20: 76 + 4 = 80

So, 4*20 = 80