OK, let's crack this. We're given 620 and our task is to multiply it by 14. Essentially, we'll be adding 620 to itself 14 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

So, 620*14 = 8680