Let's get this math done. We have 670 and we're going to multiply it by 43. This is the same as taking 670 and adding it to itself 43 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
Step 13: 8040 + 670 = 8710
Step 14: 8710 + 670 = 9380
Step 15: 9380 + 670 = 10050
Step 16: 10050 + 670 = 10720
Step 17: 10720 + 670 = 11390
Step 18: 11390 + 670 = 12060
Step 19: 12060 + 670 = 12730
Step 20: 12730 + 670 = 13400
Step 21: 13400 + 670 = 14070
Step 22: 14070 + 670 = 14740
Step 23: 14740 + 670 = 15410
Step 24: 15410 + 670 = 16080
Step 25: 16080 + 670 = 16750
Step 26: 16750 + 670 = 17420
Step 27: 17420 + 670 = 18090
Step 28: 18090 + 670 = 18760
Step 29: 18760 + 670 = 19430
Step 30: 19430 + 670 = 20100
Step 31: 20100 + 670 = 20770
Step 32: 20770 + 670 = 21440
Step 33: 21440 + 670 = 22110
Step 34: 22110 + 670 = 22780
Step 35: 22780 + 670 = 23450
Step 36: 23450 + 670 = 24120
Step 37: 24120 + 670 = 24790
Step 38: 24790 + 670 = 25460
Step 39: 25460 + 670 = 26130
Step 40: 26130 + 670 = 26800
Step 41: 26800 + 670 = 27470
Step 42: 27470 + 670 = 28140
Step 43: 28140 + 670 = 28810

So, 670*43 = 28810