Let's roll up our sleeves and solve this. We have 670 and we're going to multiply it by 12, essentially adding 670 to itself 12 times.
Step 1: 0 + 670 = 670
Step 2: 670 + 670 = 1340
Step 3: 1340 + 670 = 2010
Step 4: 2010 + 670 = 2680
Step 5: 2680 + 670 = 3350
Step 6: 3350 + 670 = 4020
Step 7: 4020 + 670 = 4690
Step 8: 4690 + 670 = 5360
Step 9: 5360 + 670 = 6030
Step 10: 6030 + 670 = 6700
Step 11: 6700 + 670 = 7370
Step 12: 7370 + 670 = 8040

So, 670*12 = 8040