OK, let's work through this together. We're starting with 402 and we're going to multiply it by 450, which means we add 402 to itself 450 times.
Step 1: 0 + 402 = 402
Step 2: 402 + 402 = 804
Step 3: 804 + 402 = 1206
Step 4: 1206 + 402 = 1608
Step 5: 1608 + 402 = 2010
Step 6: 2010 + 402 = 2412
Step 7: 2412 + 402 = 2814
Step 8: 2814 + 402 = 3216
Step 9: 3216 + 402 = 3618
Step 10: 3618 + 402 = 4020
Step 11: 4020 + 402 = 4422
Step 12: 4422 + 402 = 4824
Step 13: 4824 + 402 = 5226
Step 14: 5226 + 402 = 5628
Step 15: 5628 + 402 = 6030
Step 16: 6030 + 402 = 6432
Step 17: 6432 + 402 = 6834
Step 18: 6834 + 402 = 7236
Step 19: 7236 + 402 = 7638
Step 20: 7638 + 402 = 8040
Step 21: 8040 + 402 = 8442
Step 22: 8442 + 402 = 8844
Step 23: 8844 + 402 = 9246
Step 24: 9246 + 402 = 9648
Step 25: 9648 + 402 = 10050
Step 26: 10050 + 402 = 10452
Step 27: 10452 + 402 = 10854
Step 28: 10854 + 402 = 11256
Step 29: 11256 + 402 = 11658
Step 30: 11658 + 402 = 12060
Step 31: 12060 + 402 = 12462
Step 32: 12462 + 402 = 12864
Step 33: 12864 + 402 = 13266
Step 34: 13266 + 402 = 13668
Step 35: 13668 + 402 = 14070
Step 36: 14070 + 402 = 14472
Step 37: 14472 + 402 = 14874
Step 38: 14874 + 402 = 15276
Step 39: 15276 + 402 = 15678
Step 40: 15678 + 402 = 16080
Step 41: 16080 + 402 = 16482
Step 42: 16482 + 402 = 16884
Step 43: 16884 + 402 = 17286
Step 44: 17286 + 402 = 17688
Step 45: 17688 + 402 = 18090
Step 46: 18090 + 402 = 18492
Step 47: 18492 + 402 = 18894
Step 48: 18894 + 402 = 19296
Step 49: 19296 + 402 = 19698
Step 50: 19698 + 402 = 20100
Step 51: 20100 + 402 = 20502
Step 52: 20502 + 402 = 20904
Step 53: 20904 + 402 = 21306
Step 54: 21306 + 402 = 21708
Step 55: 21708 + 402 = 22110
Step 56: 22110 + 402 = 22512
Step 57: 22512 + 402 = 22914
Step 58: 22914 + 402 = 23316
Step 59: 23316 + 402 = 23718
Step 60: 23718 + 402 = 24120
Step 61: 24120 + 402 = 24522
Step 62: 24522 + 402 = 24924
Step 63: 24924 + 402 = 25326
Step 64: 25326 + 402 = 25728
Step 65: 25728 + 402 = 26130
Step 66: 26130 + 402 = 26532
Step 67: 26532 + 402 = 26934
Step 68: 26934 + 402 = 27336
Step 69: 27336 + 402 = 27738
Step 70: 27738 + 402 = 28140
Step 71: 28140 + 402 = 28542
Step 72: 28542 + 402 = 28944
Step 73: 28944 + 402 = 29346
Step 74: 29346 + 402 = 29748
Step 75: 29748 + 402 = 30150
Step 76: 30150 + 402 = 30552
Step 77: 30552 + 402 = 30954
Step 78: 30954 + 402 = 31356
Step 79: 31356 + 402 = 31758
Step 80: 31758 + 402 = 32160
Step 81: 32160 + 402 = 32562
Step 82: 32562 + 402 = 32964
Step 83: 32964 + 402 = 33366
Step 84: 33366 + 402 = 33768
Step 85: 33768 + 402 = 34170
Step 86: 34170 + 402 = 34572
Step 87: 34572 + 402 = 34974
Step 88: 34974 + 402 = 35376
Step 89: 35376 + 402 = 35778
Step 90: 35778 + 402 = 36180
Step 91: 36180 + 402 = 36582
Step 92: 36582 + 402 = 36984
Step 93: 36984 + 402 = 37386
Step 94: 37386 + 402 = 37788
Step 95: 37788 + 402 = 38190
Step 96: 38190 + 402 = 38592
Step 97: 38592 + 402 = 38994
Step 98: 38994 + 402 = 39396
Step 99: 39396 + 402 = 39798
Step 100: 39798 + 402 = 40200
Step 101: 40200 + 402 = 40602
Step 102: 40602 + 402 = 41004
Step 103: 41004 + 402 = 41406
Step 104: 41406 + 402 = 41808
Step 105: 41808 + 402 = 42210
Step 106: 42210 + 402 = 42612
Step 107: 42612 + 402 = 43014
Step 108: 43014 + 402 = 43416
Step 109: 43416 + 402 = 43818
Step 110: 43818 + 402 = 44220
Step 111: 44220 + 402 = 44622
Step 112: 44622 + 402 = 45024
Step 113: 45024 + 402 = 45426
Step 114: 45426 + 402 = 45828
Step 115: 45828 + 402 = 46230
Step 116: 46230 + 402 = 46632
Step 117: 46632 + 402 = 47034
Step 118: 47034 + 402 = 47436
Step 119: 47436 + 402 = 47838
Step 120: 47838 + 402 = 48240
Step 121: 48240 + 402 = 48642
Step 122: 48642 + 402 = 49044
Step 123: 49044 + 402 = 49446
Step 124: 49446 + 402 = 49848
Step 125: 49848 + 402 = 50250
Step 126: 50250 + 402 = 50652
Step 127: 50652 + 402 = 51054
Step 128: 51054 + 402 = 51456
Step 129: 51456 + 402 = 51858
Step 130: 51858 + 402 = 52260
Step 131: 52260 + 402 = 52662
Step 132: 52662 + 402 = 53064
Step 133: 53064 + 402 = 53466
Step 134: 53466 + 402 = 53868
Step 135: 53868 + 402 = 54270
Step 136: 54270 + 402 = 54672
Step 137: 54672 + 402 = 55074
Step 138: 55074 + 402 = 55476
Step 139: 55476 + 402 = 55878
Step 140: 55878 + 402 = 56280
Step 141: 56280 + 402 = 56682
Step 142: 56682 + 402 = 57084
Step 143: 57084 + 402 = 57486
Step 144: 57486 + 402 = 57888
Step 145: 57888 + 402 = 58290
Step 146: 58290 + 402 = 58692
Step 147: 58692 + 402 = 59094
Step 148: 59094 + 402 = 59496
Step 149: 59496 + 402 = 59898
Step 150: 59898 + 402 = 60300
Step 151: 60300 + 402 = 60702
Step 152: 60702 + 402 = 61104
Step 153: 61104 + 402 = 61506
Step 154: 61506 + 402 = 61908
Step 155: 61908 + 402 = 62310
Step 156: 62310 + 402 = 62712
Step 157: 62712 + 402 = 63114
Step 158: 63114 + 402 = 63516
Step 159: 63516 + 402 = 63918
Step 160: 63918 + 402 = 64320
Step 161: 64320 + 402 = 64722
Step 162: 64722 + 402 = 65124
Step 163: 65124 + 402 = 65526
Step 164: 65526 + 402 = 65928
Step 165: 65928 + 402 = 66330
Step 166: 66330 + 402 = 66732
Step 167: 66732 + 402 = 67134
Step 168: 67134 + 402 = 67536
Step 169: 67536 + 402 = 67938
Step 170: 67938 + 402 = 68340
Step 171: 68340 + 402 = 68742
Step 172: 68742 + 402 = 69144
Step 173: 69144 + 402 = 69546
Step 174: 69546 + 402 = 69948
Step 175: 69948 + 402 = 70350
Step 176: 70350 + 402 = 70752
Step 177: 70752 + 402 = 71154
Step 178: 71154 + 402 = 71556
Step 179: 71556 + 402 = 71958
Step 180: 71958 + 402 = 72360
Step 181: 72360 + 402 = 72762
Step 182: 72762 + 402 = 73164
Step 183: 73164 + 402 = 73566
Step 184: 73566 + 402 = 73968
Step 185: 73968 + 402 = 74370
Step 186: 74370 + 402 = 74772
Step 187: 74772 + 402 = 75174
Step 188: 75174 + 402 = 75576
Step 189: 75576 + 402 = 75978
Step 190: 75978 + 402 = 76380
Step 191: 76380 + 402 = 76782
Step 192: 76782 + 402 = 77184
Step 193: 77184 + 402 = 77586
Step 194: 77586 + 402 = 77988
Step 195: 77988 + 402 = 78390
Step 196: 78390 + 402 = 78792
Step 197: 78792 + 402 = 79194
Step 198: 79194 + 402 = 79596
Step 199: 79596 + 402 = 79998
Step 200: 79998 + 402 = 80400
Step 201: 80400 + 402 = 80802
Step 202: 80802 + 402 = 81204
Step 203: 81204 + 402 = 81606
Step 204: 81606 + 402 = 82008
Step 205: 82008 + 402 = 82410
Step 206: 82410 + 402 = 82812
Step 207: 82812 + 402 = 83214
Step 208: 83214 + 402 = 83616
Step 209: 83616 + 402 = 84018
Step 210: 84018 + 402 = 84420
Step 211: 84420 + 402 = 84822
Step 212: 84822 + 402 = 85224
Step 213: 85224 + 402 = 85626
Step 214: 85626 + 402 = 86028
Step 215: 86028 + 402 = 86430
Step 216: 86430 + 402 = 86832
Step 217: 86832 + 402 = 87234
Step 218: 87234 + 402 = 87636
Step 219: 87636 + 402 = 88038
Step 220: 88038 + 402 = 88440
Step 221: 88440 + 402 = 88842
Step 222: 88842 + 402 = 89244
Step 223: 89244 + 402 = 89646
Step 224: 89646 + 402 = 90048
Step 225: 90048 + 402 = 90450
Step 226: 90450 + 402 = 90852
Step 227: 90852 + 402 = 91254
Step 228: 91254 + 402 = 91656
Step 229: 91656 + 402 = 92058
Step 230: 92058 + 402 = 92460
Step 231: 92460 + 402 = 92862
Step 232: 92862 + 402 = 93264
Step 233: 93264 + 402 = 93666
Step 234: 93666 + 402 = 94068
Step 235: 94068 + 402 = 94470
Step 236: 94470 + 402 = 94872
Step 237: 94872 + 402 = 95274
Step 238: 95274 + 402 = 95676
Step 239: 95676 + 402 = 96078
Step 240: 96078 + 402 = 96480
Step 241: 96480 + 402 = 96882
Step 242: 96882 + 402 = 97284
Step 243: 97284 + 402 = 97686
Step 244: 97686 + 402 = 98088
Step 245: 98088 + 402 = 98490
Step 246: 98490 + 402 = 98892
Step 247: 98892 + 402 = 99294
Step 248: 99294 + 402 = 99696
Step 249: 99696 + 402 = 100098
Step 250: 100098 + 402 = 100500
Step 251: 100500 + 402 = 100902
Step 252: 100902 + 402 = 101304
Step 253: 101304 + 402 = 101706
Step 254: 101706 + 402 = 102108
Step 255: 102108 + 402 = 102510
Step 256: 102510 + 402 = 102912
Step 257: 102912 + 402 = 103314
Step 258: 103314 + 402 = 103716
Step 259: 103716 + 402 = 104118
Step 260: 104118 + 402 = 104520
Step 261: 104520 + 402 = 104922
Step 262: 104922 + 402 = 105324
Step 263: 105324 + 402 = 105726
Step 264: 105726 + 402 = 106128
Step 265: 106128 + 402 = 106530
Step 266: 106530 + 402 = 106932
Step 267: 106932 + 402 = 107334
Step 268: 107334 + 402 = 107736
Step 269: 107736 + 402 = 108138
Step 270: 108138 + 402 = 108540
Step 271: 108540 + 402 = 108942
Step 272: 108942 + 402 = 109344
Step 273: 109344 + 402 = 109746
Step 274: 109746 + 402 = 110148
Step 275: 110148 + 402 = 110550
Step 276: 110550 + 402 = 110952
Step 277: 110952 + 402 = 111354
Step 278: 111354 + 402 = 111756
Step 279: 111756 + 402 = 112158
Step 280: 112158 + 402 = 112560
Step 281: 112560 + 402 = 112962
Step 282: 112962 + 402 = 113364
Step 283: 113364 + 402 = 113766
Step 284: 113766 + 402 = 114168
Step 285: 114168 + 402 = 114570
Step 286: 114570 + 402 = 114972
Step 287: 114972 + 402 = 115374
Step 288: 115374 + 402 = 115776
Step 289: 115776 + 402 = 116178
Step 290: 116178 + 402 = 116580
Step 291: 116580 + 402 = 116982
Step 292: 116982 + 402 = 117384
Step 293: 117384 + 402 = 117786
Step 294: 117786 + 402 = 118188
Step 295: 118188 + 402 = 118590
Step 296: 118590 + 402 = 118992
Step 297: 118992 + 402 = 119394
Step 298: 119394 + 402 = 119796
Step 299: 119796 + 402 = 120198
Step 300: 120198 + 402 = 120600
Step 301: 120600 + 402 = 121002
Step 302: 121002 + 402 = 121404
Step 303: 121404 + 402 = 121806
Step 304: 121806 + 402 = 122208
Step 305: 122208 + 402 = 122610
Step 306: 122610 + 402 = 123012
Step 307: 123012 + 402 = 123414
Step 308: 123414 + 402 = 123816
Step 309: 123816 + 402 = 124218
Step 310: 124218 + 402 = 124620
Step 311: 124620 + 402 = 125022
Step 312: 125022 + 402 = 125424
Step 313: 125424 + 402 = 125826
Step 314: 125826 + 402 = 126228
Step 315: 126228 + 402 = 126630
Step 316: 126630 + 402 = 127032
Step 317: 127032 + 402 = 127434
Step 318: 127434 + 402 = 127836
Step 319: 127836 + 402 = 128238
Step 320: 128238 + 402 = 128640
Step 321: 128640 + 402 = 129042
Step 322: 129042 + 402 = 129444
Step 323: 129444 + 402 = 129846
Step 324: 129846 + 402 = 130248
Step 325: 130248 + 402 = 130650
Step 326: 130650 + 402 = 131052
Step 327: 131052 + 402 = 131454
Step 328: 131454 + 402 = 131856
Step 329: 131856 + 402 = 132258
Step 330: 132258 + 402 = 132660
Step 331: 132660 + 402 = 133062
Step 332: 133062 + 402 = 133464
Step 333: 133464 + 402 = 133866
Step 334: 133866 + 402 = 134268
Step 335: 134268 + 402 = 134670
Step 336: 134670 + 402 = 135072
Step 337: 135072 + 402 = 135474
Step 338: 135474 + 402 = 135876
Step 339: 135876 + 402 = 136278
Step 340: 136278 + 402 = 136680
Step 341: 136680 + 402 = 137082
Step 342: 137082 + 402 = 137484
Step 343: 137484 + 402 = 137886
Step 344: 137886 + 402 = 138288
Step 345: 138288 + 402 = 138690
Step 346: 138690 + 402 = 139092
Step 347: 139092 + 402 = 139494
Step 348: 139494 + 402 = 139896
Step 349: 139896 + 402 = 140298
Step 350: 140298 + 402 = 140700
Step 351: 140700 + 402 = 141102
Step 352: 141102 + 402 = 141504
Step 353: 141504 + 402 = 141906
Step 354: 141906 + 402 = 142308
Step 355: 142308 + 402 = 142710
Step 356: 142710 + 402 = 143112
Step 357: 143112 + 402 = 143514
Step 358: 143514 + 402 = 143916
Step 359: 143916 + 402 = 144318
Step 360: 144318 + 402 = 144720
Step 361: 144720 + 402 = 145122
Step 362: 145122 + 402 = 145524
Step 363: 145524 + 402 = 145926
Step 364: 145926 + 402 = 146328
Step 365: 146328 + 402 = 146730
Step 366: 146730 + 402 = 147132
Step 367: 147132 + 402 = 147534
Step 368: 147534 + 402 = 147936
Step 369: 147936 + 402 = 148338
Step 370: 148338 + 402 = 148740
Step 371: 148740 + 402 = 149142
Step 372: 149142 + 402 = 149544
Step 373: 149544 + 402 = 149946
Step 374: 149946 + 402 = 150348
Step 375: 150348 + 402 = 150750
Step 376: 150750 + 402 = 151152
Step 377: 151152 + 402 = 151554
Step 378: 151554 + 402 = 151956
Step 379: 151956 + 402 = 152358
Step 380: 152358 + 402 = 152760
Step 381: 152760 + 402 = 153162
Step 382: 153162 + 402 = 153564
Step 383: 153564 + 402 = 153966
Step 384: 153966 + 402 = 154368
Step 385: 154368 + 402 = 154770
Step 386: 154770 + 402 = 155172
Step 387: 155172 + 402 = 155574
Step 388: 155574 + 402 = 155976
Step 389: 155976 + 402 = 156378
Step 390: 156378 + 402 = 156780
Step 391: 156780 + 402 = 157182
Step 392: 157182 + 402 = 157584
Step 393: 157584 + 402 = 157986
Step 394: 157986 + 402 = 158388
Step 395: 158388 + 402 = 158790
Step 396: 158790 + 402 = 159192
Step 397: 159192 + 402 = 159594
Step 398: 159594 + 402 = 159996
Step 399: 159996 + 402 = 160398
Step 400: 160398 + 402 = 160800
Step 401: 160800 + 402 = 161202
Step 402: 161202 + 402 = 161604
Step 403: 161604 + 402 = 162006
Step 404: 162006 + 402 = 162408
Step 405: 162408 + 402 = 162810
Step 406: 162810 + 402 = 163212
Step 407: 163212 + 402 = 163614
Step 408: 163614 + 402 = 164016
Step 409: 164016 + 402 = 164418
Step 410: 164418 + 402 = 164820
Step 411: 164820 + 402 = 165222
Step 412: 165222 + 402 = 165624
Step 413: 165624 + 402 = 166026
Step 414: 166026 + 402 = 166428
Step 415: 166428 + 402 = 166830
Step 416: 166830 + 402 = 167232
Step 417: 167232 + 402 = 167634
Step 418: 167634 + 402 = 168036
Step 419: 168036 + 402 = 168438
Step 420: 168438 + 402 = 168840
Step 421: 168840 + 402 = 169242
Step 422: 169242 + 402 = 169644
Step 423: 169644 + 402 = 170046
Step 424: 170046 + 402 = 170448
Step 425: 170448 + 402 = 170850
Step 426: 170850 + 402 = 171252
Step 427: 171252 + 402 = 171654
Step 428: 171654 + 402 = 172056
Step 429: 172056 + 402 = 172458
Step 430: 172458 + 402 = 172860
Step 431: 172860 + 402 = 173262
Step 432: 173262 + 402 = 173664
Step 433: 173664 + 402 = 174066
Step 434: 174066 + 402 = 174468
Step 435: 174468 + 402 = 174870
Step 436: 174870 + 402 = 175272
Step 437: 175272 + 402 = 175674
Step 438: 175674 + 402 = 176076
Step 439: 176076 + 402 = 176478
Step 440: 176478 + 402 = 176880
Step 441: 176880 + 402 = 177282
Step 442: 177282 + 402 = 177684
Step 443: 177684 + 402 = 178086
Step 444: 178086 + 402 = 178488
Step 445: 178488 + 402 = 178890
Step 446: 178890 + 402 = 179292
Step 447: 179292 + 402 = 179694
Step 448: 179694 + 402 = 180096
Step 449: 180096 + 402 = 180498
Step 450: 180498 + 402 = 180900

So, 402*450 = 180900