Let's get this math done. We have 620 and we're going to multiply it by 34. This is the same as taking 620 and adding it to itself 34 times.
Step 1: 0 + 620 = 620
Step 2: 620 + 620 = 1240
Step 3: 1240 + 620 = 1860
Step 4: 1860 + 620 = 2480
Step 5: 2480 + 620 = 3100
Step 6: 3100 + 620 = 3720
Step 7: 3720 + 620 = 4340
Step 8: 4340 + 620 = 4960
Step 9: 4960 + 620 = 5580
Step 10: 5580 + 620 = 6200
Step 11: 6200 + 620 = 6820
Step 12: 6820 + 620 = 7440
Step 13: 7440 + 620 = 8060
Step 14: 8060 + 620 = 8680
Step 15: 8680 + 620 = 9300
Step 16: 9300 + 620 = 9920
Step 17: 9920 + 620 = 10540
Step 18: 10540 + 620 = 11160
Step 19: 11160 + 620 = 11780
Step 20: 11780 + 620 = 12400
Step 21: 12400 + 620 = 13020
Step 22: 13020 + 620 = 13640
Step 23: 13640 + 620 = 14260
Step 24: 14260 + 620 = 14880
Step 25: 14880 + 620 = 15500
Step 26: 15500 + 620 = 16120
Step 27: 16120 + 620 = 16740
Step 28: 16740 + 620 = 17360
Step 29: 17360 + 620 = 17980
Step 30: 17980 + 620 = 18600
Step 31: 18600 + 620 = 19220
Step 32: 19220 + 620 = 19840
Step 33: 19840 + 620 = 20460
Step 34: 20460 + 620 = 21080

So, 620*34 = 21080