Let's roll up our sleeves and solve this. We have 870 and we're going to multiply it by 197, essentially adding 870 to itself 197 times.
Step 1: 0 + 870 = 870
Step 2: 870 + 870 = 1740
Step 3: 1740 + 870 = 2610
Step 4: 2610 + 870 = 3480
Step 5: 3480 + 870 = 4350
Step 6: 4350 + 870 = 5220
Step 7: 5220 + 870 = 6090
Step 8: 6090 + 870 = 6960
Step 9: 6960 + 870 = 7830
Step 10: 7830 + 870 = 8700
Step 11: 8700 + 870 = 9570
Step 12: 9570 + 870 = 10440
Step 13: 10440 + 870 = 11310
Step 14: 11310 + 870 = 12180
Step 15: 12180 + 870 = 13050
Step 16: 13050 + 870 = 13920
Step 17: 13920 + 870 = 14790
Step 18: 14790 + 870 = 15660
Step 19: 15660 + 870 = 16530
Step 20: 16530 + 870 = 17400
Step 21: 17400 + 870 = 18270
Step 22: 18270 + 870 = 19140
Step 23: 19140 + 870 = 20010
Step 24: 20010 + 870 = 20880
Step 25: 20880 + 870 = 21750
Step 26: 21750 + 870 = 22620
Step 27: 22620 + 870 = 23490
Step 28: 23490 + 870 = 24360
Step 29: 24360 + 870 = 25230
Step 30: 25230 + 870 = 26100
Step 31: 26100 + 870 = 26970
Step 32: 26970 + 870 = 27840
Step 33: 27840 + 870 = 28710
Step 34: 28710 + 870 = 29580
Step 35: 29580 + 870 = 30450
Step 36: 30450 + 870 = 31320
Step 37: 31320 + 870 = 32190
Step 38: 32190 + 870 = 33060
Step 39: 33060 + 870 = 33930
Step 40: 33930 + 870 = 34800
Step 41: 34800 + 870 = 35670
Step 42: 35670 + 870 = 36540
Step 43: 36540 + 870 = 37410
Step 44: 37410 + 870 = 38280
Step 45: 38280 + 870 = 39150
Step 46: 39150 + 870 = 40020
Step 47: 40020 + 870 = 40890
Step 48: 40890 + 870 = 41760
Step 49: 41760 + 870 = 42630
Step 50: 42630 + 870 = 43500
Step 51: 43500 + 870 = 44370
Step 52: 44370 + 870 = 45240
Step 53: 45240 + 870 = 46110
Step 54: 46110 + 870 = 46980
Step 55: 46980 + 870 = 47850
Step 56: 47850 + 870 = 48720
Step 57: 48720 + 870 = 49590
Step 58: 49590 + 870 = 50460
Step 59: 50460 + 870 = 51330
Step 60: 51330 + 870 = 52200
Step 61: 52200 + 870 = 53070
Step 62: 53070 + 870 = 53940
Step 63: 53940 + 870 = 54810
Step 64: 54810 + 870 = 55680
Step 65: 55680 + 870 = 56550
Step 66: 56550 + 870 = 57420
Step 67: 57420 + 870 = 58290
Step 68: 58290 + 870 = 59160
Step 69: 59160 + 870 = 60030
Step 70: 60030 + 870 = 60900
Step 71: 60900 + 870 = 61770
Step 72: 61770 + 870 = 62640
Step 73: 62640 + 870 = 63510
Step 74: 63510 + 870 = 64380
Step 75: 64380 + 870 = 65250
Step 76: 65250 + 870 = 66120
Step 77: 66120 + 870 = 66990
Step 78: 66990 + 870 = 67860
Step 79: 67860 + 870 = 68730
Step 80: 68730 + 870 = 69600
Step 81: 69600 + 870 = 70470
Step 82: 70470 + 870 = 71340
Step 83: 71340 + 870 = 72210
Step 84: 72210 + 870 = 73080
Step 85: 73080 + 870 = 73950
Step 86: 73950 + 870 = 74820
Step 87: 74820 + 870 = 75690
Step 88: 75690 + 870 = 76560
Step 89: 76560 + 870 = 77430
Step 90: 77430 + 870 = 78300
Step 91: 78300 + 870 = 79170
Step 92: 79170 + 870 = 80040
Step 93: 80040 + 870 = 80910
Step 94: 80910 + 870 = 81780
Step 95: 81780 + 870 = 82650
Step 96: 82650 + 870 = 83520
Step 97: 83520 + 870 = 84390
Step 98: 84390 + 870 = 85260
Step 99: 85260 + 870 = 86130
Step 100: 86130 + 870 = 87000
Step 101: 87000 + 870 = 87870
Step 102: 87870 + 870 = 88740
Step 103: 88740 + 870 = 89610
Step 104: 89610 + 870 = 90480
Step 105: 90480 + 870 = 91350
Step 106: 91350 + 870 = 92220
Step 107: 92220 + 870 = 93090
Step 108: 93090 + 870 = 93960
Step 109: 93960 + 870 = 94830
Step 110: 94830 + 870 = 95700
Step 111: 95700 + 870 = 96570
Step 112: 96570 + 870 = 97440
Step 113: 97440 + 870 = 98310
Step 114: 98310 + 870 = 99180
Step 115: 99180 + 870 = 100050
Step 116: 100050 + 870 = 100920
Step 117: 100920 + 870 = 101790
Step 118: 101790 + 870 = 102660
Step 119: 102660 + 870 = 103530
Step 120: 103530 + 870 = 104400
Step 121: 104400 + 870 = 105270
Step 122: 105270 + 870 = 106140
Step 123: 106140 + 870 = 107010
Step 124: 107010 + 870 = 107880
Step 125: 107880 + 870 = 108750
Step 126: 108750 + 870 = 109620
Step 127: 109620 + 870 = 110490
Step 128: 110490 + 870 = 111360
Step 129: 111360 + 870 = 112230
Step 130: 112230 + 870 = 113100
Step 131: 113100 + 870 = 113970
Step 132: 113970 + 870 = 114840
Step 133: 114840 + 870 = 115710
Step 134: 115710 + 870 = 116580
Step 135: 116580 + 870 = 117450
Step 136: 117450 + 870 = 118320
Step 137: 118320 + 870 = 119190
Step 138: 119190 + 870 = 120060
Step 139: 120060 + 870 = 120930
Step 140: 120930 + 870 = 121800
Step 141: 121800 + 870 = 122670
Step 142: 122670 + 870 = 123540
Step 143: 123540 + 870 = 124410
Step 144: 124410 + 870 = 125280
Step 145: 125280 + 870 = 126150
Step 146: 126150 + 870 = 127020
Step 147: 127020 + 870 = 127890
Step 148: 127890 + 870 = 128760
Step 149: 128760 + 870 = 129630
Step 150: 129630 + 870 = 130500
Step 151: 130500 + 870 = 131370
Step 152: 131370 + 870 = 132240
Step 153: 132240 + 870 = 133110
Step 154: 133110 + 870 = 133980
Step 155: 133980 + 870 = 134850
Step 156: 134850 + 870 = 135720
Step 157: 135720 + 870 = 136590
Step 158: 136590 + 870 = 137460
Step 159: 137460 + 870 = 138330
Step 160: 138330 + 870 = 139200
Step 161: 139200 + 870 = 140070
Step 162: 140070 + 870 = 140940
Step 163: 140940 + 870 = 141810
Step 164: 141810 + 870 = 142680
Step 165: 142680 + 870 = 143550
Step 166: 143550 + 870 = 144420
Step 167: 144420 + 870 = 145290
Step 168: 145290 + 870 = 146160
Step 169: 146160 + 870 = 147030
Step 170: 147030 + 870 = 147900
Step 171: 147900 + 870 = 148770
Step 172: 148770 + 870 = 149640
Step 173: 149640 + 870 = 150510
Step 174: 150510 + 870 = 151380
Step 175: 151380 + 870 = 152250
Step 176: 152250 + 870 = 153120
Step 177: 153120 + 870 = 153990
Step 178: 153990 + 870 = 154860
Step 179: 154860 + 870 = 155730
Step 180: 155730 + 870 = 156600
Step 181: 156600 + 870 = 157470
Step 182: 157470 + 870 = 158340
Step 183: 158340 + 870 = 159210
Step 184: 159210 + 870 = 160080
Step 185: 160080 + 870 = 160950
Step 186: 160950 + 870 = 161820
Step 187: 161820 + 870 = 162690
Step 188: 162690 + 870 = 163560
Step 189: 163560 + 870 = 164430
Step 190: 164430 + 870 = 165300
Step 191: 165300 + 870 = 166170
Step 192: 166170 + 870 = 167040
Step 193: 167040 + 870 = 167910
Step 194: 167910 + 870 = 168780
Step 195: 168780 + 870 = 169650
Step 196: 169650 + 870 = 170520
Step 197: 170520 + 870 = 171390

So, 870*197 = 171390