Let's get this math done. We have 869 and we're going to multiply it by 210. This is the same as taking 869 and adding it to itself 210 times.
Step 1: 0 + 869 = 869
Step 2: 869 + 869 = 1738
Step 3: 1738 + 869 = 2607
Step 4: 2607 + 869 = 3476
Step 5: 3476 + 869 = 4345
Step 6: 4345 + 869 = 5214
Step 7: 5214 + 869 = 6083
Step 8: 6083 + 869 = 6952
Step 9: 6952 + 869 = 7821
Step 10: 7821 + 869 = 8690
Step 11: 8690 + 869 = 9559
Step 12: 9559 + 869 = 10428
Step 13: 10428 + 869 = 11297
Step 14: 11297 + 869 = 12166
Step 15: 12166 + 869 = 13035
Step 16: 13035 + 869 = 13904
Step 17: 13904 + 869 = 14773
Step 18: 14773 + 869 = 15642
Step 19: 15642 + 869 = 16511
Step 20: 16511 + 869 = 17380
Step 21: 17380 + 869 = 18249
Step 22: 18249 + 869 = 19118
Step 23: 19118 + 869 = 19987
Step 24: 19987 + 869 = 20856
Step 25: 20856 + 869 = 21725
Step 26: 21725 + 869 = 22594
Step 27: 22594 + 869 = 23463
Step 28: 23463 + 869 = 24332
Step 29: 24332 + 869 = 25201
Step 30: 25201 + 869 = 26070
Step 31: 26070 + 869 = 26939
Step 32: 26939 + 869 = 27808
Step 33: 27808 + 869 = 28677
Step 34: 28677 + 869 = 29546
Step 35: 29546 + 869 = 30415
Step 36: 30415 + 869 = 31284
Step 37: 31284 + 869 = 32153
Step 38: 32153 + 869 = 33022
Step 39: 33022 + 869 = 33891
Step 40: 33891 + 869 = 34760
Step 41: 34760 + 869 = 35629
Step 42: 35629 + 869 = 36498
Step 43: 36498 + 869 = 37367
Step 44: 37367 + 869 = 38236
Step 45: 38236 + 869 = 39105
Step 46: 39105 + 869 = 39974
Step 47: 39974 + 869 = 40843
Step 48: 40843 + 869 = 41712
Step 49: 41712 + 869 = 42581
Step 50: 42581 + 869 = 43450
Step 51: 43450 + 869 = 44319
Step 52: 44319 + 869 = 45188
Step 53: 45188 + 869 = 46057
Step 54: 46057 + 869 = 46926
Step 55: 46926 + 869 = 47795
Step 56: 47795 + 869 = 48664
Step 57: 48664 + 869 = 49533
Step 58: 49533 + 869 = 50402
Step 59: 50402 + 869 = 51271
Step 60: 51271 + 869 = 52140
Step 61: 52140 + 869 = 53009
Step 62: 53009 + 869 = 53878
Step 63: 53878 + 869 = 54747
Step 64: 54747 + 869 = 55616
Step 65: 55616 + 869 = 56485
Step 66: 56485 + 869 = 57354
Step 67: 57354 + 869 = 58223
Step 68: 58223 + 869 = 59092
Step 69: 59092 + 869 = 59961
Step 70: 59961 + 869 = 60830
Step 71: 60830 + 869 = 61699
Step 72: 61699 + 869 = 62568
Step 73: 62568 + 869 = 63437
Step 74: 63437 + 869 = 64306
Step 75: 64306 + 869 = 65175
Step 76: 65175 + 869 = 66044
Step 77: 66044 + 869 = 66913
Step 78: 66913 + 869 = 67782
Step 79: 67782 + 869 = 68651
Step 80: 68651 + 869 = 69520
Step 81: 69520 + 869 = 70389
Step 82: 70389 + 869 = 71258
Step 83: 71258 + 869 = 72127
Step 84: 72127 + 869 = 72996
Step 85: 72996 + 869 = 73865
Step 86: 73865 + 869 = 74734
Step 87: 74734 + 869 = 75603
Step 88: 75603 + 869 = 76472
Step 89: 76472 + 869 = 77341
Step 90: 77341 + 869 = 78210
Step 91: 78210 + 869 = 79079
Step 92: 79079 + 869 = 79948
Step 93: 79948 + 869 = 80817
Step 94: 80817 + 869 = 81686
Step 95: 81686 + 869 = 82555
Step 96: 82555 + 869 = 83424
Step 97: 83424 + 869 = 84293
Step 98: 84293 + 869 = 85162
Step 99: 85162 + 869 = 86031
Step 100: 86031 + 869 = 86900
Step 101: 86900 + 869 = 87769
Step 102: 87769 + 869 = 88638
Step 103: 88638 + 869 = 89507
Step 104: 89507 + 869 = 90376
Step 105: 90376 + 869 = 91245
Step 106: 91245 + 869 = 92114
Step 107: 92114 + 869 = 92983
Step 108: 92983 + 869 = 93852
Step 109: 93852 + 869 = 94721
Step 110: 94721 + 869 = 95590
Step 111: 95590 + 869 = 96459
Step 112: 96459 + 869 = 97328
Step 113: 97328 + 869 = 98197
Step 114: 98197 + 869 = 99066
Step 115: 99066 + 869 = 99935
Step 116: 99935 + 869 = 100804
Step 117: 100804 + 869 = 101673
Step 118: 101673 + 869 = 102542
Step 119: 102542 + 869 = 103411
Step 120: 103411 + 869 = 104280
Step 121: 104280 + 869 = 105149
Step 122: 105149 + 869 = 106018
Step 123: 106018 + 869 = 106887
Step 124: 106887 + 869 = 107756
Step 125: 107756 + 869 = 108625
Step 126: 108625 + 869 = 109494
Step 127: 109494 + 869 = 110363
Step 128: 110363 + 869 = 111232
Step 129: 111232 + 869 = 112101
Step 130: 112101 + 869 = 112970
Step 131: 112970 + 869 = 113839
Step 132: 113839 + 869 = 114708
Step 133: 114708 + 869 = 115577
Step 134: 115577 + 869 = 116446
Step 135: 116446 + 869 = 117315
Step 136: 117315 + 869 = 118184
Step 137: 118184 + 869 = 119053
Step 138: 119053 + 869 = 119922
Step 139: 119922 + 869 = 120791
Step 140: 120791 + 869 = 121660
Step 141: 121660 + 869 = 122529
Step 142: 122529 + 869 = 123398
Step 143: 123398 + 869 = 124267
Step 144: 124267 + 869 = 125136
Step 145: 125136 + 869 = 126005
Step 146: 126005 + 869 = 126874
Step 147: 126874 + 869 = 127743
Step 148: 127743 + 869 = 128612
Step 149: 128612 + 869 = 129481
Step 150: 129481 + 869 = 130350
Step 151: 130350 + 869 = 131219
Step 152: 131219 + 869 = 132088
Step 153: 132088 + 869 = 132957
Step 154: 132957 + 869 = 133826
Step 155: 133826 + 869 = 134695
Step 156: 134695 + 869 = 135564
Step 157: 135564 + 869 = 136433
Step 158: 136433 + 869 = 137302
Step 159: 137302 + 869 = 138171
Step 160: 138171 + 869 = 139040
Step 161: 139040 + 869 = 139909
Step 162: 139909 + 869 = 140778
Step 163: 140778 + 869 = 141647
Step 164: 141647 + 869 = 142516
Step 165: 142516 + 869 = 143385
Step 166: 143385 + 869 = 144254
Step 167: 144254 + 869 = 145123
Step 168: 145123 + 869 = 145992
Step 169: 145992 + 869 = 146861
Step 170: 146861 + 869 = 147730
Step 171: 147730 + 869 = 148599
Step 172: 148599 + 869 = 149468
Step 173: 149468 + 869 = 150337
Step 174: 150337 + 869 = 151206
Step 175: 151206 + 869 = 152075
Step 176: 152075 + 869 = 152944
Step 177: 152944 + 869 = 153813
Step 178: 153813 + 869 = 154682
Step 179: 154682 + 869 = 155551
Step 180: 155551 + 869 = 156420
Step 181: 156420 + 869 = 157289
Step 182: 157289 + 869 = 158158
Step 183: 158158 + 869 = 159027
Step 184: 159027 + 869 = 159896
Step 185: 159896 + 869 = 160765
Step 186: 160765 + 869 = 161634
Step 187: 161634 + 869 = 162503
Step 188: 162503 + 869 = 163372
Step 189: 163372 + 869 = 164241
Step 190: 164241 + 869 = 165110
Step 191: 165110 + 869 = 165979
Step 192: 165979 + 869 = 166848
Step 193: 166848 + 869 = 167717
Step 194: 167717 + 869 = 168586
Step 195: 168586 + 869 = 169455
Step 196: 169455 + 869 = 170324
Step 197: 170324 + 869 = 171193
Step 198: 171193 + 869 = 172062
Step 199: 172062 + 869 = 172931
Step 200: 172931 + 869 = 173800
Step 201: 173800 + 869 = 174669
Step 202: 174669 + 869 = 175538
Step 203: 175538 + 869 = 176407
Step 204: 176407 + 869 = 177276
Step 205: 177276 + 869 = 178145
Step 206: 178145 + 869 = 179014
Step 207: 179014 + 869 = 179883
Step 208: 179883 + 869 = 180752
Step 209: 180752 + 869 = 181621
Step 210: 181621 + 869 = 182490

So, 869*210 = 182490