Without delay, let's solve this. We've got 537 and we will be multiplying it by 12, that is, adding 537 to itself 12 times.
Step 1: 0 + 537 = 537
Step 2: 537 + 537 = 1074
Step 3: 1074 + 537 = 1611
Step 4: 1611 + 537 = 2148
Step 5: 2148 + 537 = 2685
Step 6: 2685 + 537 = 3222
Step 7: 3222 + 537 = 3759
Step 8: 3759 + 537 = 4296
Step 9: 4296 + 537 = 4833
Step 10: 4833 + 537 = 5370
Step 11: 5370 + 537 = 5907
Step 12: 5907 + 537 = 6444

So, 537*12 = 6444