Let's roll up our sleeves and solve this. We have 346 and we're going to multiply it by 12, essentially adding 346 to itself 12 times.
Step 1: 0 + 346 = 346
Step 2: 346 + 346 = 692
Step 3: 692 + 346 = 1038
Step 4: 1038 + 346 = 1384
Step 5: 1384 + 346 = 1730
Step 6: 1730 + 346 = 2076
Step 7: 2076 + 346 = 2422
Step 8: 2422 + 346 = 2768
Step 9: 2768 + 346 = 3114
Step 10: 3114 + 346 = 3460
Step 11: 3460 + 346 = 3806
Step 12: 3806 + 346 = 4152

So, 346*12 = 4152