Let's get this math done. We have 423 and we're going to multiply it by 12. This is the same as taking 423 and adding it to itself 12 times.
Step 1: 0 + 423 = 423
Step 2: 423 + 423 = 846
Step 3: 846 + 423 = 1269
Step 4: 1269 + 423 = 1692
Step 5: 1692 + 423 = 2115
Step 6: 2115 + 423 = 2538
Step 7: 2538 + 423 = 2961
Step 8: 2961 + 423 = 3384
Step 9: 3384 + 423 = 3807
Step 10: 3807 + 423 = 4230
Step 11: 4230 + 423 = 4653
Step 12: 4653 + 423 = 5076

So, 423*12 = 5076