OK, let's work through this together. We're starting with 904 and we're going to multiply it by 213, which means we add 904 to itself 213 times.
Step 1: 0 + 904 = 904
Step 2: 904 + 904 = 1808
Step 3: 1808 + 904 = 2712
Step 4: 2712 + 904 = 3616
Step 5: 3616 + 904 = 4520
Step 6: 4520 + 904 = 5424
Step 7: 5424 + 904 = 6328
Step 8: 6328 + 904 = 7232
Step 9: 7232 + 904 = 8136
Step 10: 8136 + 904 = 9040
Step 11: 9040 + 904 = 9944
Step 12: 9944 + 904 = 10848
Step 13: 10848 + 904 = 11752
Step 14: 11752 + 904 = 12656
Step 15: 12656 + 904 = 13560
Step 16: 13560 + 904 = 14464
Step 17: 14464 + 904 = 15368
Step 18: 15368 + 904 = 16272
Step 19: 16272 + 904 = 17176
Step 20: 17176 + 904 = 18080
Step 21: 18080 + 904 = 18984
Step 22: 18984 + 904 = 19888
Step 23: 19888 + 904 = 20792
Step 24: 20792 + 904 = 21696
Step 25: 21696 + 904 = 22600
Step 26: 22600 + 904 = 23504
Step 27: 23504 + 904 = 24408
Step 28: 24408 + 904 = 25312
Step 29: 25312 + 904 = 26216
Step 30: 26216 + 904 = 27120
Step 31: 27120 + 904 = 28024
Step 32: 28024 + 904 = 28928
Step 33: 28928 + 904 = 29832
Step 34: 29832 + 904 = 30736
Step 35: 30736 + 904 = 31640
Step 36: 31640 + 904 = 32544
Step 37: 32544 + 904 = 33448
Step 38: 33448 + 904 = 34352
Step 39: 34352 + 904 = 35256
Step 40: 35256 + 904 = 36160
Step 41: 36160 + 904 = 37064
Step 42: 37064 + 904 = 37968
Step 43: 37968 + 904 = 38872
Step 44: 38872 + 904 = 39776
Step 45: 39776 + 904 = 40680
Step 46: 40680 + 904 = 41584
Step 47: 41584 + 904 = 42488
Step 48: 42488 + 904 = 43392
Step 49: 43392 + 904 = 44296
Step 50: 44296 + 904 = 45200
Step 51: 45200 + 904 = 46104
Step 52: 46104 + 904 = 47008
Step 53: 47008 + 904 = 47912
Step 54: 47912 + 904 = 48816
Step 55: 48816 + 904 = 49720
Step 56: 49720 + 904 = 50624
Step 57: 50624 + 904 = 51528
Step 58: 51528 + 904 = 52432
Step 59: 52432 + 904 = 53336
Step 60: 53336 + 904 = 54240
Step 61: 54240 + 904 = 55144
Step 62: 55144 + 904 = 56048
Step 63: 56048 + 904 = 56952
Step 64: 56952 + 904 = 57856
Step 65: 57856 + 904 = 58760
Step 66: 58760 + 904 = 59664
Step 67: 59664 + 904 = 60568
Step 68: 60568 + 904 = 61472
Step 69: 61472 + 904 = 62376
Step 70: 62376 + 904 = 63280
Step 71: 63280 + 904 = 64184
Step 72: 64184 + 904 = 65088
Step 73: 65088 + 904 = 65992
Step 74: 65992 + 904 = 66896
Step 75: 66896 + 904 = 67800
Step 76: 67800 + 904 = 68704
Step 77: 68704 + 904 = 69608
Step 78: 69608 + 904 = 70512
Step 79: 70512 + 904 = 71416
Step 80: 71416 + 904 = 72320
Step 81: 72320 + 904 = 73224
Step 82: 73224 + 904 = 74128
Step 83: 74128 + 904 = 75032
Step 84: 75032 + 904 = 75936
Step 85: 75936 + 904 = 76840
Step 86: 76840 + 904 = 77744
Step 87: 77744 + 904 = 78648
Step 88: 78648 + 904 = 79552
Step 89: 79552 + 904 = 80456
Step 90: 80456 + 904 = 81360
Step 91: 81360 + 904 = 82264
Step 92: 82264 + 904 = 83168
Step 93: 83168 + 904 = 84072
Step 94: 84072 + 904 = 84976
Step 95: 84976 + 904 = 85880
Step 96: 85880 + 904 = 86784
Step 97: 86784 + 904 = 87688
Step 98: 87688 + 904 = 88592
Step 99: 88592 + 904 = 89496
Step 100: 89496 + 904 = 90400
Step 101: 90400 + 904 = 91304
Step 102: 91304 + 904 = 92208
Step 103: 92208 + 904 = 93112
Step 104: 93112 + 904 = 94016
Step 105: 94016 + 904 = 94920
Step 106: 94920 + 904 = 95824
Step 107: 95824 + 904 = 96728
Step 108: 96728 + 904 = 97632
Step 109: 97632 + 904 = 98536
Step 110: 98536 + 904 = 99440
Step 111: 99440 + 904 = 100344
Step 112: 100344 + 904 = 101248
Step 113: 101248 + 904 = 102152
Step 114: 102152 + 904 = 103056
Step 115: 103056 + 904 = 103960
Step 116: 103960 + 904 = 104864
Step 117: 104864 + 904 = 105768
Step 118: 105768 + 904 = 106672
Step 119: 106672 + 904 = 107576
Step 120: 107576 + 904 = 108480
Step 121: 108480 + 904 = 109384
Step 122: 109384 + 904 = 110288
Step 123: 110288 + 904 = 111192
Step 124: 111192 + 904 = 112096
Step 125: 112096 + 904 = 113000
Step 126: 113000 + 904 = 113904
Step 127: 113904 + 904 = 114808
Step 128: 114808 + 904 = 115712
Step 129: 115712 + 904 = 116616
Step 130: 116616 + 904 = 117520
Step 131: 117520 + 904 = 118424
Step 132: 118424 + 904 = 119328
Step 133: 119328 + 904 = 120232
Step 134: 120232 + 904 = 121136
Step 135: 121136 + 904 = 122040
Step 136: 122040 + 904 = 122944
Step 137: 122944 + 904 = 123848
Step 138: 123848 + 904 = 124752
Step 139: 124752 + 904 = 125656
Step 140: 125656 + 904 = 126560
Step 141: 126560 + 904 = 127464
Step 142: 127464 + 904 = 128368
Step 143: 128368 + 904 = 129272
Step 144: 129272 + 904 = 130176
Step 145: 130176 + 904 = 131080
Step 146: 131080 + 904 = 131984
Step 147: 131984 + 904 = 132888
Step 148: 132888 + 904 = 133792
Step 149: 133792 + 904 = 134696
Step 150: 134696 + 904 = 135600
Step 151: 135600 + 904 = 136504
Step 152: 136504 + 904 = 137408
Step 153: 137408 + 904 = 138312
Step 154: 138312 + 904 = 139216
Step 155: 139216 + 904 = 140120
Step 156: 140120 + 904 = 141024
Step 157: 141024 + 904 = 141928
Step 158: 141928 + 904 = 142832
Step 159: 142832 + 904 = 143736
Step 160: 143736 + 904 = 144640
Step 161: 144640 + 904 = 145544
Step 162: 145544 + 904 = 146448
Step 163: 146448 + 904 = 147352
Step 164: 147352 + 904 = 148256
Step 165: 148256 + 904 = 149160
Step 166: 149160 + 904 = 150064
Step 167: 150064 + 904 = 150968
Step 168: 150968 + 904 = 151872
Step 169: 151872 + 904 = 152776
Step 170: 152776 + 904 = 153680
Step 171: 153680 + 904 = 154584
Step 172: 154584 + 904 = 155488
Step 173: 155488 + 904 = 156392
Step 174: 156392 + 904 = 157296
Step 175: 157296 + 904 = 158200
Step 176: 158200 + 904 = 159104
Step 177: 159104 + 904 = 160008
Step 178: 160008 + 904 = 160912
Step 179: 160912 + 904 = 161816
Step 180: 161816 + 904 = 162720
Step 181: 162720 + 904 = 163624
Step 182: 163624 + 904 = 164528
Step 183: 164528 + 904 = 165432
Step 184: 165432 + 904 = 166336
Step 185: 166336 + 904 = 167240
Step 186: 167240 + 904 = 168144
Step 187: 168144 + 904 = 169048
Step 188: 169048 + 904 = 169952
Step 189: 169952 + 904 = 170856
Step 190: 170856 + 904 = 171760
Step 191: 171760 + 904 = 172664
Step 192: 172664 + 904 = 173568
Step 193: 173568 + 904 = 174472
Step 194: 174472 + 904 = 175376
Step 195: 175376 + 904 = 176280
Step 196: 176280 + 904 = 177184
Step 197: 177184 + 904 = 178088
Step 198: 178088 + 904 = 178992
Step 199: 178992 + 904 = 179896
Step 200: 179896 + 904 = 180800
Step 201: 180800 + 904 = 181704
Step 202: 181704 + 904 = 182608
Step 203: 182608 + 904 = 183512
Step 204: 183512 + 904 = 184416
Step 205: 184416 + 904 = 185320
Step 206: 185320 + 904 = 186224
Step 207: 186224 + 904 = 187128
Step 208: 187128 + 904 = 188032
Step 209: 188032 + 904 = 188936
Step 210: 188936 + 904 = 189840
Step 211: 189840 + 904 = 190744
Step 212: 190744 + 904 = 191648
Step 213: 191648 + 904 = 192552

So, 904*213 = 192552