OK, let's work through this together. We're starting with 980 and we're going to multiply it by 105, which means we add 980 to itself 105 times.
Step 1: 0 + 980 = 980
Step 2: 980 + 980 = 1960
Step 3: 1960 + 980 = 2940
Step 4: 2940 + 980 = 3920
Step 5: 3920 + 980 = 4900
Step 6: 4900 + 980 = 5880
Step 7: 5880 + 980 = 6860
Step 8: 6860 + 980 = 7840
Step 9: 7840 + 980 = 8820
Step 10: 8820 + 980 = 9800
Step 11: 9800 + 980 = 10780
Step 12: 10780 + 980 = 11760
Step 13: 11760 + 980 = 12740
Step 14: 12740 + 980 = 13720
Step 15: 13720 + 980 = 14700
Step 16: 14700 + 980 = 15680
Step 17: 15680 + 980 = 16660
Step 18: 16660 + 980 = 17640
Step 19: 17640 + 980 = 18620
Step 20: 18620 + 980 = 19600
Step 21: 19600 + 980 = 20580
Step 22: 20580 + 980 = 21560
Step 23: 21560 + 980 = 22540
Step 24: 22540 + 980 = 23520
Step 25: 23520 + 980 = 24500
Step 26: 24500 + 980 = 25480
Step 27: 25480 + 980 = 26460
Step 28: 26460 + 980 = 27440
Step 29: 27440 + 980 = 28420
Step 30: 28420 + 980 = 29400
Step 31: 29400 + 980 = 30380
Step 32: 30380 + 980 = 31360
Step 33: 31360 + 980 = 32340
Step 34: 32340 + 980 = 33320
Step 35: 33320 + 980 = 34300
Step 36: 34300 + 980 = 35280
Step 37: 35280 + 980 = 36260
Step 38: 36260 + 980 = 37240
Step 39: 37240 + 980 = 38220
Step 40: 38220 + 980 = 39200
Step 41: 39200 + 980 = 40180
Step 42: 40180 + 980 = 41160
Step 43: 41160 + 980 = 42140
Step 44: 42140 + 980 = 43120
Step 45: 43120 + 980 = 44100
Step 46: 44100 + 980 = 45080
Step 47: 45080 + 980 = 46060
Step 48: 46060 + 980 = 47040
Step 49: 47040 + 980 = 48020
Step 50: 48020 + 980 = 49000
Step 51: 49000 + 980 = 49980
Step 52: 49980 + 980 = 50960
Step 53: 50960 + 980 = 51940
Step 54: 51940 + 980 = 52920
Step 55: 52920 + 980 = 53900
Step 56: 53900 + 980 = 54880
Step 57: 54880 + 980 = 55860
Step 58: 55860 + 980 = 56840
Step 59: 56840 + 980 = 57820
Step 60: 57820 + 980 = 58800
Step 61: 58800 + 980 = 59780
Step 62: 59780 + 980 = 60760
Step 63: 60760 + 980 = 61740
Step 64: 61740 + 980 = 62720
Step 65: 62720 + 980 = 63700
Step 66: 63700 + 980 = 64680
Step 67: 64680 + 980 = 65660
Step 68: 65660 + 980 = 66640
Step 69: 66640 + 980 = 67620
Step 70: 67620 + 980 = 68600
Step 71: 68600 + 980 = 69580
Step 72: 69580 + 980 = 70560
Step 73: 70560 + 980 = 71540
Step 74: 71540 + 980 = 72520
Step 75: 72520 + 980 = 73500
Step 76: 73500 + 980 = 74480
Step 77: 74480 + 980 = 75460
Step 78: 75460 + 980 = 76440
Step 79: 76440 + 980 = 77420
Step 80: 77420 + 980 = 78400
Step 81: 78400 + 980 = 79380
Step 82: 79380 + 980 = 80360
Step 83: 80360 + 980 = 81340
Step 84: 81340 + 980 = 82320
Step 85: 82320 + 980 = 83300
Step 86: 83300 + 980 = 84280
Step 87: 84280 + 980 = 85260
Step 88: 85260 + 980 = 86240
Step 89: 86240 + 980 = 87220
Step 90: 87220 + 980 = 88200
Step 91: 88200 + 980 = 89180
Step 92: 89180 + 980 = 90160
Step 93: 90160 + 980 = 91140
Step 94: 91140 + 980 = 92120
Step 95: 92120 + 980 = 93100
Step 96: 93100 + 980 = 94080
Step 97: 94080 + 980 = 95060
Step 98: 95060 + 980 = 96040
Step 99: 96040 + 980 = 97020
Step 100: 97020 + 980 = 98000
Step 101: 98000 + 980 = 98980
Step 102: 98980 + 980 = 99960
Step 103: 99960 + 980 = 100940
Step 104: 100940 + 980 = 101920
Step 105: 101920 + 980 = 102900

So, 980*105 = 102900