Alright, let's solve this math problem step by step. First, we have the number 3. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 40. So, we're going to take the number 3 and add it to itself 40 times.
Step 1: 0 + 3 = 3
Step 2: 3 + 3 = 6
Step 3: 6 + 3 = 9
Step 4: 9 + 3 = 12
Step 5: 12 + 3 = 15
Step 6: 15 + 3 = 18
Step 7: 18 + 3 = 21
Step 8: 21 + 3 = 24
Step 9: 24 + 3 = 27
Step 10: 27 + 3 = 30
Step 11: 30 + 3 = 33
Step 12: 33 + 3 = 36
Step 13: 36 + 3 = 39
Step 14: 39 + 3 = 42
Step 15: 42 + 3 = 45
Step 16: 45 + 3 = 48
Step 17: 48 + 3 = 51
Step 18: 51 + 3 = 54
Step 19: 54 + 3 = 57
Step 20: 57 + 3 = 60
Step 21: 60 + 3 = 63
Step 22: 63 + 3 = 66
Step 23: 66 + 3 = 69
Step 24: 69 + 3 = 72
Step 25: 72 + 3 = 75
Step 26: 75 + 3 = 78
Step 27: 78 + 3 = 81
Step 28: 81 + 3 = 84
Step 29: 84 + 3 = 87
Step 30: 87 + 3 = 90
Step 31: 90 + 3 = 93
Step 32: 93 + 3 = 96
Step 33: 96 + 3 = 99
Step 34: 99 + 3 = 102
Step 35: 102 + 3 = 105
Step 36: 105 + 3 = 108
Step 37: 108 + 3 = 111
Step 38: 111 + 3 = 114
Step 39: 114 + 3 = 117
Step 40: 117 + 3 = 120

So, 3*40 = 120