OK, let's work through this together. We're starting with 830 and we're going to multiply it by 20, which means we add 830 to itself 20 times.
Step 1: 0 + 830 = 830
Step 2: 830 + 830 = 1660
Step 3: 1660 + 830 = 2490
Step 4: 2490 + 830 = 3320
Step 5: 3320 + 830 = 4150
Step 6: 4150 + 830 = 4980
Step 7: 4980 + 830 = 5810
Step 8: 5810 + 830 = 6640
Step 9: 6640 + 830 = 7470
Step 10: 7470 + 830 = 8300
Step 11: 8300 + 830 = 9130
Step 12: 9130 + 830 = 9960
Step 13: 9960 + 830 = 10790
Step 14: 10790 + 830 = 11620
Step 15: 11620 + 830 = 12450
Step 16: 12450 + 830 = 13280
Step 17: 13280 + 830 = 14110
Step 18: 14110 + 830 = 14940
Step 19: 14940 + 830 = 15770
Step 20: 15770 + 830 = 16600

So, 830*20 = 16600