Sure thing! We've got 864 and we're gonna multiply it by 409. That's the same as adding 864 to itself 409 times.
Step 1: 0 + 864 = 864
Step 2: 864 + 864 = 1728
Step 3: 1728 + 864 = 2592
Step 4: 2592 + 864 = 3456
Step 5: 3456 + 864 = 4320
Step 6: 4320 + 864 = 5184
Step 7: 5184 + 864 = 6048
Step 8: 6048 + 864 = 6912
Step 9: 6912 + 864 = 7776
Step 10: 7776 + 864 = 8640
Step 11: 8640 + 864 = 9504
Step 12: 9504 + 864 = 10368
Step 13: 10368 + 864 = 11232
Step 14: 11232 + 864 = 12096
Step 15: 12096 + 864 = 12960
Step 16: 12960 + 864 = 13824
Step 17: 13824 + 864 = 14688
Step 18: 14688 + 864 = 15552
Step 19: 15552 + 864 = 16416
Step 20: 16416 + 864 = 17280
Step 21: 17280 + 864 = 18144
Step 22: 18144 + 864 = 19008
Step 23: 19008 + 864 = 19872
Step 24: 19872 + 864 = 20736
Step 25: 20736 + 864 = 21600
Step 26: 21600 + 864 = 22464
Step 27: 22464 + 864 = 23328
Step 28: 23328 + 864 = 24192
Step 29: 24192 + 864 = 25056
Step 30: 25056 + 864 = 25920
Step 31: 25920 + 864 = 26784
Step 32: 26784 + 864 = 27648
Step 33: 27648 + 864 = 28512
Step 34: 28512 + 864 = 29376
Step 35: 29376 + 864 = 30240
Step 36: 30240 + 864 = 31104
Step 37: 31104 + 864 = 31968
Step 38: 31968 + 864 = 32832
Step 39: 32832 + 864 = 33696
Step 40: 33696 + 864 = 34560
Step 41: 34560 + 864 = 35424
Step 42: 35424 + 864 = 36288
Step 43: 36288 + 864 = 37152
Step 44: 37152 + 864 = 38016
Step 45: 38016 + 864 = 38880
Step 46: 38880 + 864 = 39744
Step 47: 39744 + 864 = 40608
Step 48: 40608 + 864 = 41472
Step 49: 41472 + 864 = 42336
Step 50: 42336 + 864 = 43200
Step 51: 43200 + 864 = 44064
Step 52: 44064 + 864 = 44928
Step 53: 44928 + 864 = 45792
Step 54: 45792 + 864 = 46656
Step 55: 46656 + 864 = 47520
Step 56: 47520 + 864 = 48384
Step 57: 48384 + 864 = 49248
Step 58: 49248 + 864 = 50112
Step 59: 50112 + 864 = 50976
Step 60: 50976 + 864 = 51840
Step 61: 51840 + 864 = 52704
Step 62: 52704 + 864 = 53568
Step 63: 53568 + 864 = 54432
Step 64: 54432 + 864 = 55296
Step 65: 55296 + 864 = 56160
Step 66: 56160 + 864 = 57024
Step 67: 57024 + 864 = 57888
Step 68: 57888 + 864 = 58752
Step 69: 58752 + 864 = 59616
Step 70: 59616 + 864 = 60480
Step 71: 60480 + 864 = 61344
Step 72: 61344 + 864 = 62208
Step 73: 62208 + 864 = 63072
Step 74: 63072 + 864 = 63936
Step 75: 63936 + 864 = 64800
Step 76: 64800 + 864 = 65664
Step 77: 65664 + 864 = 66528
Step 78: 66528 + 864 = 67392
Step 79: 67392 + 864 = 68256
Step 80: 68256 + 864 = 69120
Step 81: 69120 + 864 = 69984
Step 82: 69984 + 864 = 70848
Step 83: 70848 + 864 = 71712
Step 84: 71712 + 864 = 72576
Step 85: 72576 + 864 = 73440
Step 86: 73440 + 864 = 74304
Step 87: 74304 + 864 = 75168
Step 88: 75168 + 864 = 76032
Step 89: 76032 + 864 = 76896
Step 90: 76896 + 864 = 77760
Step 91: 77760 + 864 = 78624
Step 92: 78624 + 864 = 79488
Step 93: 79488 + 864 = 80352
Step 94: 80352 + 864 = 81216
Step 95: 81216 + 864 = 82080
Step 96: 82080 + 864 = 82944
Step 97: 82944 + 864 = 83808
Step 98: 83808 + 864 = 84672
Step 99: 84672 + 864 = 85536
Step 100: 85536 + 864 = 86400
Step 101: 86400 + 864 = 87264
Step 102: 87264 + 864 = 88128
Step 103: 88128 + 864 = 88992
Step 104: 88992 + 864 = 89856
Step 105: 89856 + 864 = 90720
Step 106: 90720 + 864 = 91584
Step 107: 91584 + 864 = 92448
Step 108: 92448 + 864 = 93312
Step 109: 93312 + 864 = 94176
Step 110: 94176 + 864 = 95040
Step 111: 95040 + 864 = 95904
Step 112: 95904 + 864 = 96768
Step 113: 96768 + 864 = 97632
Step 114: 97632 + 864 = 98496
Step 115: 98496 + 864 = 99360
Step 116: 99360 + 864 = 100224
Step 117: 100224 + 864 = 101088
Step 118: 101088 + 864 = 101952
Step 119: 101952 + 864 = 102816
Step 120: 102816 + 864 = 103680
Step 121: 103680 + 864 = 104544
Step 122: 104544 + 864 = 105408
Step 123: 105408 + 864 = 106272
Step 124: 106272 + 864 = 107136
Step 125: 107136 + 864 = 108000
Step 126: 108000 + 864 = 108864
Step 127: 108864 + 864 = 109728
Step 128: 109728 + 864 = 110592
Step 129: 110592 + 864 = 111456
Step 130: 111456 + 864 = 112320
Step 131: 112320 + 864 = 113184
Step 132: 113184 + 864 = 114048
Step 133: 114048 + 864 = 114912
Step 134: 114912 + 864 = 115776
Step 135: 115776 + 864 = 116640
Step 136: 116640 + 864 = 117504
Step 137: 117504 + 864 = 118368
Step 138: 118368 + 864 = 119232
Step 139: 119232 + 864 = 120096
Step 140: 120096 + 864 = 120960
Step 141: 120960 + 864 = 121824
Step 142: 121824 + 864 = 122688
Step 143: 122688 + 864 = 123552
Step 144: 123552 + 864 = 124416
Step 145: 124416 + 864 = 125280
Step 146: 125280 + 864 = 126144
Step 147: 126144 + 864 = 127008
Step 148: 127008 + 864 = 127872
Step 149: 127872 + 864 = 128736
Step 150: 128736 + 864 = 129600
Step 151: 129600 + 864 = 130464
Step 152: 130464 + 864 = 131328
Step 153: 131328 + 864 = 132192
Step 154: 132192 + 864 = 133056
Step 155: 133056 + 864 = 133920
Step 156: 133920 + 864 = 134784
Step 157: 134784 + 864 = 135648
Step 158: 135648 + 864 = 136512
Step 159: 136512 + 864 = 137376
Step 160: 137376 + 864 = 138240
Step 161: 138240 + 864 = 139104
Step 162: 139104 + 864 = 139968
Step 163: 139968 + 864 = 140832
Step 164: 140832 + 864 = 141696
Step 165: 141696 + 864 = 142560
Step 166: 142560 + 864 = 143424
Step 167: 143424 + 864 = 144288
Step 168: 144288 + 864 = 145152
Step 169: 145152 + 864 = 146016
Step 170: 146016 + 864 = 146880
Step 171: 146880 + 864 = 147744
Step 172: 147744 + 864 = 148608
Step 173: 148608 + 864 = 149472
Step 174: 149472 + 864 = 150336
Step 175: 150336 + 864 = 151200
Step 176: 151200 + 864 = 152064
Step 177: 152064 + 864 = 152928
Step 178: 152928 + 864 = 153792
Step 179: 153792 + 864 = 154656
Step 180: 154656 + 864 = 155520
Step 181: 155520 + 864 = 156384
Step 182: 156384 + 864 = 157248
Step 183: 157248 + 864 = 158112
Step 184: 158112 + 864 = 158976
Step 185: 158976 + 864 = 159840
Step 186: 159840 + 864 = 160704
Step 187: 160704 + 864 = 161568
Step 188: 161568 + 864 = 162432
Step 189: 162432 + 864 = 163296
Step 190: 163296 + 864 = 164160
Step 191: 164160 + 864 = 165024
Step 192: 165024 + 864 = 165888
Step 193: 165888 + 864 = 166752
Step 194: 166752 + 864 = 167616
Step 195: 167616 + 864 = 168480
Step 196: 168480 + 864 = 169344
Step 197: 169344 + 864 = 170208
Step 198: 170208 + 864 = 171072
Step 199: 171072 + 864 = 171936
Step 200: 171936 + 864 = 172800
Step 201: 172800 + 864 = 173664
Step 202: 173664 + 864 = 174528
Step 203: 174528 + 864 = 175392
Step 204: 175392 + 864 = 176256
Step 205: 176256 + 864 = 177120
Step 206: 177120 + 864 = 177984
Step 207: 177984 + 864 = 178848
Step 208: 178848 + 864 = 179712
Step 209: 179712 + 864 = 180576
Step 210: 180576 + 864 = 181440
Step 211: 181440 + 864 = 182304
Step 212: 182304 + 864 = 183168
Step 213: 183168 + 864 = 184032
Step 214: 184032 + 864 = 184896
Step 215: 184896 + 864 = 185760
Step 216: 185760 + 864 = 186624
Step 217: 186624 + 864 = 187488
Step 218: 187488 + 864 = 188352
Step 219: 188352 + 864 = 189216
Step 220: 189216 + 864 = 190080
Step 221: 190080 + 864 = 190944
Step 222: 190944 + 864 = 191808
Step 223: 191808 + 864 = 192672
Step 224: 192672 + 864 = 193536
Step 225: 193536 + 864 = 194400
Step 226: 194400 + 864 = 195264
Step 227: 195264 + 864 = 196128
Step 228: 196128 + 864 = 196992
Step 229: 196992 + 864 = 197856
Step 230: 197856 + 864 = 198720
Step 231: 198720 + 864 = 199584
Step 232: 199584 + 864 = 200448
Step 233: 200448 + 864 = 201312
Step 234: 201312 + 864 = 202176
Step 235: 202176 + 864 = 203040
Step 236: 203040 + 864 = 203904
Step 237: 203904 + 864 = 204768
Step 238: 204768 + 864 = 205632
Step 239: 205632 + 864 = 206496
Step 240: 206496 + 864 = 207360
Step 241: 207360 + 864 = 208224
Step 242: 208224 + 864 = 209088
Step 243: 209088 + 864 = 209952
Step 244: 209952 + 864 = 210816
Step 245: 210816 + 864 = 211680
Step 246: 211680 + 864 = 212544
Step 247: 212544 + 864 = 213408
Step 248: 213408 + 864 = 214272
Step 249: 214272 + 864 = 215136
Step 250: 215136 + 864 = 216000
Step 251: 216000 + 864 = 216864
Step 252: 216864 + 864 = 217728
Step 253: 217728 + 864 = 218592
Step 254: 218592 + 864 = 219456
Step 255: 219456 + 864 = 220320
Step 256: 220320 + 864 = 221184
Step 257: 221184 + 864 = 222048
Step 258: 222048 + 864 = 222912
Step 259: 222912 + 864 = 223776
Step 260: 223776 + 864 = 224640
Step 261: 224640 + 864 = 225504
Step 262: 225504 + 864 = 226368
Step 263: 226368 + 864 = 227232
Step 264: 227232 + 864 = 228096
Step 265: 228096 + 864 = 228960
Step 266: 228960 + 864 = 229824
Step 267: 229824 + 864 = 230688
Step 268: 230688 + 864 = 231552
Step 269: 231552 + 864 = 232416
Step 270: 232416 + 864 = 233280
Step 271: 233280 + 864 = 234144
Step 272: 234144 + 864 = 235008
Step 273: 235008 + 864 = 235872
Step 274: 235872 + 864 = 236736
Step 275: 236736 + 864 = 237600
Step 276: 237600 + 864 = 238464
Step 277: 238464 + 864 = 239328
Step 278: 239328 + 864 = 240192
Step 279: 240192 + 864 = 241056
Step 280: 241056 + 864 = 241920
Step 281: 241920 + 864 = 242784
Step 282: 242784 + 864 = 243648
Step 283: 243648 + 864 = 244512
Step 284: 244512 + 864 = 245376
Step 285: 245376 + 864 = 246240
Step 286: 246240 + 864 = 247104
Step 287: 247104 + 864 = 247968
Step 288: 247968 + 864 = 248832
Step 289: 248832 + 864 = 249696
Step 290: 249696 + 864 = 250560
Step 291: 250560 + 864 = 251424
Step 292: 251424 + 864 = 252288
Step 293: 252288 + 864 = 253152
Step 294: 253152 + 864 = 254016
Step 295: 254016 + 864 = 254880
Step 296: 254880 + 864 = 255744
Step 297: 255744 + 864 = 256608
Step 298: 256608 + 864 = 257472
Step 299: 257472 + 864 = 258336
Step 300: 258336 + 864 = 259200
Step 301: 259200 + 864 = 260064
Step 302: 260064 + 864 = 260928
Step 303: 260928 + 864 = 261792
Step 304: 261792 + 864 = 262656
Step 305: 262656 + 864 = 263520
Step 306: 263520 + 864 = 264384
Step 307: 264384 + 864 = 265248
Step 308: 265248 + 864 = 266112
Step 309: 266112 + 864 = 266976
Step 310: 266976 + 864 = 267840
Step 311: 267840 + 864 = 268704
Step 312: 268704 + 864 = 269568
Step 313: 269568 + 864 = 270432
Step 314: 270432 + 864 = 271296
Step 315: 271296 + 864 = 272160
Step 316: 272160 + 864 = 273024
Step 317: 273024 + 864 = 273888
Step 318: 273888 + 864 = 274752
Step 319: 274752 + 864 = 275616
Step 320: 275616 + 864 = 276480
Step 321: 276480 + 864 = 277344
Step 322: 277344 + 864 = 278208
Step 323: 278208 + 864 = 279072
Step 324: 279072 + 864 = 279936
Step 325: 279936 + 864 = 280800
Step 326: 280800 + 864 = 281664
Step 327: 281664 + 864 = 282528
Step 328: 282528 + 864 = 283392
Step 329: 283392 + 864 = 284256
Step 330: 284256 + 864 = 285120
Step 331: 285120 + 864 = 285984
Step 332: 285984 + 864 = 286848
Step 333: 286848 + 864 = 287712
Step 334: 287712 + 864 = 288576
Step 335: 288576 + 864 = 289440
Step 336: 289440 + 864 = 290304
Step 337: 290304 + 864 = 291168
Step 338: 291168 + 864 = 292032
Step 339: 292032 + 864 = 292896
Step 340: 292896 + 864 = 293760
Step 341: 293760 + 864 = 294624
Step 342: 294624 + 864 = 295488
Step 343: 295488 + 864 = 296352
Step 344: 296352 + 864 = 297216
Step 345: 297216 + 864 = 298080
Step 346: 298080 + 864 = 298944
Step 347: 298944 + 864 = 299808
Step 348: 299808 + 864 = 300672
Step 349: 300672 + 864 = 301536
Step 350: 301536 + 864 = 302400
Step 351: 302400 + 864 = 303264
Step 352: 303264 + 864 = 304128
Step 353: 304128 + 864 = 304992
Step 354: 304992 + 864 = 305856
Step 355: 305856 + 864 = 306720
Step 356: 306720 + 864 = 307584
Step 357: 307584 + 864 = 308448
Step 358: 308448 + 864 = 309312
Step 359: 309312 + 864 = 310176
Step 360: 310176 + 864 = 311040
Step 361: 311040 + 864 = 311904
Step 362: 311904 + 864 = 312768
Step 363: 312768 + 864 = 313632
Step 364: 313632 + 864 = 314496
Step 365: 314496 + 864 = 315360
Step 366: 315360 + 864 = 316224
Step 367: 316224 + 864 = 317088
Step 368: 317088 + 864 = 317952
Step 369: 317952 + 864 = 318816
Step 370: 318816 + 864 = 319680
Step 371: 319680 + 864 = 320544
Step 372: 320544 + 864 = 321408
Step 373: 321408 + 864 = 322272
Step 374: 322272 + 864 = 323136
Step 375: 323136 + 864 = 324000
Step 376: 324000 + 864 = 324864
Step 377: 324864 + 864 = 325728
Step 378: 325728 + 864 = 326592
Step 379: 326592 + 864 = 327456
Step 380: 327456 + 864 = 328320
Step 381: 328320 + 864 = 329184
Step 382: 329184 + 864 = 330048
Step 383: 330048 + 864 = 330912
Step 384: 330912 + 864 = 331776
Step 385: 331776 + 864 = 332640
Step 386: 332640 + 864 = 333504
Step 387: 333504 + 864 = 334368
Step 388: 334368 + 864 = 335232
Step 389: 335232 + 864 = 336096
Step 390: 336096 + 864 = 336960
Step 391: 336960 + 864 = 337824
Step 392: 337824 + 864 = 338688
Step 393: 338688 + 864 = 339552
Step 394: 339552 + 864 = 340416
Step 395: 340416 + 864 = 341280
Step 396: 341280 + 864 = 342144
Step 397: 342144 + 864 = 343008
Step 398: 343008 + 864 = 343872
Step 399: 343872 + 864 = 344736
Step 400: 344736 + 864 = 345600
Step 401: 345600 + 864 = 346464
Step 402: 346464 + 864 = 347328
Step 403: 347328 + 864 = 348192
Step 404: 348192 + 864 = 349056
Step 405: 349056 + 864 = 349920
Step 406: 349920 + 864 = 350784
Step 407: 350784 + 864 = 351648
Step 408: 351648 + 864 = 352512
Step 409: 352512 + 864 = 353376

So, 864*409 = 353376