OK, let's work through this together. We're starting with 337 and we're going to multiply it by 12, which means we add 337 to itself 12 times.
Step 1: 0 + 337 = 337
Step 2: 337 + 337 = 674
Step 3: 674 + 337 = 1011
Step 4: 1011 + 337 = 1348
Step 5: 1348 + 337 = 1685
Step 6: 1685 + 337 = 2022
Step 7: 2022 + 337 = 2359
Step 8: 2359 + 337 = 2696
Step 9: 2696 + 337 = 3033
Step 10: 3033 + 337 = 3370
Step 11: 3370 + 337 = 3707
Step 12: 3707 + 337 = 4044

So, 337*12 = 4044