Alright, let's solve this math problem step by step. First, we have the number 688. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 456. So, we're going to take the number 688 and add it to itself 456 times.
Step 1: 0 + 688 = 688
Step 2: 688 + 688 = 1376
Step 3: 1376 + 688 = 2064
Step 4: 2064 + 688 = 2752
Step 5: 2752 + 688 = 3440
Step 6: 3440 + 688 = 4128
Step 7: 4128 + 688 = 4816
Step 8: 4816 + 688 = 5504
Step 9: 5504 + 688 = 6192
Step 10: 6192 + 688 = 6880
Step 11: 6880 + 688 = 7568
Step 12: 7568 + 688 = 8256
Step 13: 8256 + 688 = 8944
Step 14: 8944 + 688 = 9632
Step 15: 9632 + 688 = 10320
Step 16: 10320 + 688 = 11008
Step 17: 11008 + 688 = 11696
Step 18: 11696 + 688 = 12384
Step 19: 12384 + 688 = 13072
Step 20: 13072 + 688 = 13760
Step 21: 13760 + 688 = 14448
Step 22: 14448 + 688 = 15136
Step 23: 15136 + 688 = 15824
Step 24: 15824 + 688 = 16512
Step 25: 16512 + 688 = 17200
Step 26: 17200 + 688 = 17888
Step 27: 17888 + 688 = 18576
Step 28: 18576 + 688 = 19264
Step 29: 19264 + 688 = 19952
Step 30: 19952 + 688 = 20640
Step 31: 20640 + 688 = 21328
Step 32: 21328 + 688 = 22016
Step 33: 22016 + 688 = 22704
Step 34: 22704 + 688 = 23392
Step 35: 23392 + 688 = 24080
Step 36: 24080 + 688 = 24768
Step 37: 24768 + 688 = 25456
Step 38: 25456 + 688 = 26144
Step 39: 26144 + 688 = 26832
Step 40: 26832 + 688 = 27520
Step 41: 27520 + 688 = 28208
Step 42: 28208 + 688 = 28896
Step 43: 28896 + 688 = 29584
Step 44: 29584 + 688 = 30272
Step 45: 30272 + 688 = 30960
Step 46: 30960 + 688 = 31648
Step 47: 31648 + 688 = 32336
Step 48: 32336 + 688 = 33024
Step 49: 33024 + 688 = 33712
Step 50: 33712 + 688 = 34400
Step 51: 34400 + 688 = 35088
Step 52: 35088 + 688 = 35776
Step 53: 35776 + 688 = 36464
Step 54: 36464 + 688 = 37152
Step 55: 37152 + 688 = 37840
Step 56: 37840 + 688 = 38528
Step 57: 38528 + 688 = 39216
Step 58: 39216 + 688 = 39904
Step 59: 39904 + 688 = 40592
Step 60: 40592 + 688 = 41280
Step 61: 41280 + 688 = 41968
Step 62: 41968 + 688 = 42656
Step 63: 42656 + 688 = 43344
Step 64: 43344 + 688 = 44032
Step 65: 44032 + 688 = 44720
Step 66: 44720 + 688 = 45408
Step 67: 45408 + 688 = 46096
Step 68: 46096 + 688 = 46784
Step 69: 46784 + 688 = 47472
Step 70: 47472 + 688 = 48160
Step 71: 48160 + 688 = 48848
Step 72: 48848 + 688 = 49536
Step 73: 49536 + 688 = 50224
Step 74: 50224 + 688 = 50912
Step 75: 50912 + 688 = 51600
Step 76: 51600 + 688 = 52288
Step 77: 52288 + 688 = 52976
Step 78: 52976 + 688 = 53664
Step 79: 53664 + 688 = 54352
Step 80: 54352 + 688 = 55040
Step 81: 55040 + 688 = 55728
Step 82: 55728 + 688 = 56416
Step 83: 56416 + 688 = 57104
Step 84: 57104 + 688 = 57792
Step 85: 57792 + 688 = 58480
Step 86: 58480 + 688 = 59168
Step 87: 59168 + 688 = 59856
Step 88: 59856 + 688 = 60544
Step 89: 60544 + 688 = 61232
Step 90: 61232 + 688 = 61920
Step 91: 61920 + 688 = 62608
Step 92: 62608 + 688 = 63296
Step 93: 63296 + 688 = 63984
Step 94: 63984 + 688 = 64672
Step 95: 64672 + 688 = 65360
Step 96: 65360 + 688 = 66048
Step 97: 66048 + 688 = 66736
Step 98: 66736 + 688 = 67424
Step 99: 67424 + 688 = 68112
Step 100: 68112 + 688 = 68800
Step 101: 68800 + 688 = 69488
Step 102: 69488 + 688 = 70176
Step 103: 70176 + 688 = 70864
Step 104: 70864 + 688 = 71552
Step 105: 71552 + 688 = 72240
Step 106: 72240 + 688 = 72928
Step 107: 72928 + 688 = 73616
Step 108: 73616 + 688 = 74304
Step 109: 74304 + 688 = 74992
Step 110: 74992 + 688 = 75680
Step 111: 75680 + 688 = 76368
Step 112: 76368 + 688 = 77056
Step 113: 77056 + 688 = 77744
Step 114: 77744 + 688 = 78432
Step 115: 78432 + 688 = 79120
Step 116: 79120 + 688 = 79808
Step 117: 79808 + 688 = 80496
Step 118: 80496 + 688 = 81184
Step 119: 81184 + 688 = 81872
Step 120: 81872 + 688 = 82560
Step 121: 82560 + 688 = 83248
Step 122: 83248 + 688 = 83936
Step 123: 83936 + 688 = 84624
Step 124: 84624 + 688 = 85312
Step 125: 85312 + 688 = 86000
Step 126: 86000 + 688 = 86688
Step 127: 86688 + 688 = 87376
Step 128: 87376 + 688 = 88064
Step 129: 88064 + 688 = 88752
Step 130: 88752 + 688 = 89440
Step 131: 89440 + 688 = 90128
Step 132: 90128 + 688 = 90816
Step 133: 90816 + 688 = 91504
Step 134: 91504 + 688 = 92192
Step 135: 92192 + 688 = 92880
Step 136: 92880 + 688 = 93568
Step 137: 93568 + 688 = 94256
Step 138: 94256 + 688 = 94944
Step 139: 94944 + 688 = 95632
Step 140: 95632 + 688 = 96320
Step 141: 96320 + 688 = 97008
Step 142: 97008 + 688 = 97696
Step 143: 97696 + 688 = 98384
Step 144: 98384 + 688 = 99072
Step 145: 99072 + 688 = 99760
Step 146: 99760 + 688 = 100448
Step 147: 100448 + 688 = 101136
Step 148: 101136 + 688 = 101824
Step 149: 101824 + 688 = 102512
Step 150: 102512 + 688 = 103200
Step 151: 103200 + 688 = 103888
Step 152: 103888 + 688 = 104576
Step 153: 104576 + 688 = 105264
Step 154: 105264 + 688 = 105952
Step 155: 105952 + 688 = 106640
Step 156: 106640 + 688 = 107328
Step 157: 107328 + 688 = 108016
Step 158: 108016 + 688 = 108704
Step 159: 108704 + 688 = 109392
Step 160: 109392 + 688 = 110080
Step 161: 110080 + 688 = 110768
Step 162: 110768 + 688 = 111456
Step 163: 111456 + 688 = 112144
Step 164: 112144 + 688 = 112832
Step 165: 112832 + 688 = 113520
Step 166: 113520 + 688 = 114208
Step 167: 114208 + 688 = 114896
Step 168: 114896 + 688 = 115584
Step 169: 115584 + 688 = 116272
Step 170: 116272 + 688 = 116960
Step 171: 116960 + 688 = 117648
Step 172: 117648 + 688 = 118336
Step 173: 118336 + 688 = 119024
Step 174: 119024 + 688 = 119712
Step 175: 119712 + 688 = 120400
Step 176: 120400 + 688 = 121088
Step 177: 121088 + 688 = 121776
Step 178: 121776 + 688 = 122464
Step 179: 122464 + 688 = 123152
Step 180: 123152 + 688 = 123840
Step 181: 123840 + 688 = 124528
Step 182: 124528 + 688 = 125216
Step 183: 125216 + 688 = 125904
Step 184: 125904 + 688 = 126592
Step 185: 126592 + 688 = 127280
Step 186: 127280 + 688 = 127968
Step 187: 127968 + 688 = 128656
Step 188: 128656 + 688 = 129344
Step 189: 129344 + 688 = 130032
Step 190: 130032 + 688 = 130720
Step 191: 130720 + 688 = 131408
Step 192: 131408 + 688 = 132096
Step 193: 132096 + 688 = 132784
Step 194: 132784 + 688 = 133472
Step 195: 133472 + 688 = 134160
Step 196: 134160 + 688 = 134848
Step 197: 134848 + 688 = 135536
Step 198: 135536 + 688 = 136224
Step 199: 136224 + 688 = 136912
Step 200: 136912 + 688 = 137600
Step 201: 137600 + 688 = 138288
Step 202: 138288 + 688 = 138976
Step 203: 138976 + 688 = 139664
Step 204: 139664 + 688 = 140352
Step 205: 140352 + 688 = 141040
Step 206: 141040 + 688 = 141728
Step 207: 141728 + 688 = 142416
Step 208: 142416 + 688 = 143104
Step 209: 143104 + 688 = 143792
Step 210: 143792 + 688 = 144480
Step 211: 144480 + 688 = 145168
Step 212: 145168 + 688 = 145856
Step 213: 145856 + 688 = 146544
Step 214: 146544 + 688 = 147232
Step 215: 147232 + 688 = 147920
Step 216: 147920 + 688 = 148608
Step 217: 148608 + 688 = 149296
Step 218: 149296 + 688 = 149984
Step 219: 149984 + 688 = 150672
Step 220: 150672 + 688 = 151360
Step 221: 151360 + 688 = 152048
Step 222: 152048 + 688 = 152736
Step 223: 152736 + 688 = 153424
Step 224: 153424 + 688 = 154112
Step 225: 154112 + 688 = 154800
Step 226: 154800 + 688 = 155488
Step 227: 155488 + 688 = 156176
Step 228: 156176 + 688 = 156864
Step 229: 156864 + 688 = 157552
Step 230: 157552 + 688 = 158240
Step 231: 158240 + 688 = 158928
Step 232: 158928 + 688 = 159616
Step 233: 159616 + 688 = 160304
Step 234: 160304 + 688 = 160992
Step 235: 160992 + 688 = 161680
Step 236: 161680 + 688 = 162368
Step 237: 162368 + 688 = 163056
Step 238: 163056 + 688 = 163744
Step 239: 163744 + 688 = 164432
Step 240: 164432 + 688 = 165120
Step 241: 165120 + 688 = 165808
Step 242: 165808 + 688 = 166496
Step 243: 166496 + 688 = 167184
Step 244: 167184 + 688 = 167872
Step 245: 167872 + 688 = 168560
Step 246: 168560 + 688 = 169248
Step 247: 169248 + 688 = 169936
Step 248: 169936 + 688 = 170624
Step 249: 170624 + 688 = 171312
Step 250: 171312 + 688 = 172000
Step 251: 172000 + 688 = 172688
Step 252: 172688 + 688 = 173376
Step 253: 173376 + 688 = 174064
Step 254: 174064 + 688 = 174752
Step 255: 174752 + 688 = 175440
Step 256: 175440 + 688 = 176128
Step 257: 176128 + 688 = 176816
Step 258: 176816 + 688 = 177504
Step 259: 177504 + 688 = 178192
Step 260: 178192 + 688 = 178880
Step 261: 178880 + 688 = 179568
Step 262: 179568 + 688 = 180256
Step 263: 180256 + 688 = 180944
Step 264: 180944 + 688 = 181632
Step 265: 181632 + 688 = 182320
Step 266: 182320 + 688 = 183008
Step 267: 183008 + 688 = 183696
Step 268: 183696 + 688 = 184384
Step 269: 184384 + 688 = 185072
Step 270: 185072 + 688 = 185760
Step 271: 185760 + 688 = 186448
Step 272: 186448 + 688 = 187136
Step 273: 187136 + 688 = 187824
Step 274: 187824 + 688 = 188512
Step 275: 188512 + 688 = 189200
Step 276: 189200 + 688 = 189888
Step 277: 189888 + 688 = 190576
Step 278: 190576 + 688 = 191264
Step 279: 191264 + 688 = 191952
Step 280: 191952 + 688 = 192640
Step 281: 192640 + 688 = 193328
Step 282: 193328 + 688 = 194016
Step 283: 194016 + 688 = 194704
Step 284: 194704 + 688 = 195392
Step 285: 195392 + 688 = 196080
Step 286: 196080 + 688 = 196768
Step 287: 196768 + 688 = 197456
Step 288: 197456 + 688 = 198144
Step 289: 198144 + 688 = 198832
Step 290: 198832 + 688 = 199520
Step 291: 199520 + 688 = 200208
Step 292: 200208 + 688 = 200896
Step 293: 200896 + 688 = 201584
Step 294: 201584 + 688 = 202272
Step 295: 202272 + 688 = 202960
Step 296: 202960 + 688 = 203648
Step 297: 203648 + 688 = 204336
Step 298: 204336 + 688 = 205024
Step 299: 205024 + 688 = 205712
Step 300: 205712 + 688 = 206400
Step 301: 206400 + 688 = 207088
Step 302: 207088 + 688 = 207776
Step 303: 207776 + 688 = 208464
Step 304: 208464 + 688 = 209152
Step 305: 209152 + 688 = 209840
Step 306: 209840 + 688 = 210528
Step 307: 210528 + 688 = 211216
Step 308: 211216 + 688 = 211904
Step 309: 211904 + 688 = 212592
Step 310: 212592 + 688 = 213280
Step 311: 213280 + 688 = 213968
Step 312: 213968 + 688 = 214656
Step 313: 214656 + 688 = 215344
Step 314: 215344 + 688 = 216032
Step 315: 216032 + 688 = 216720
Step 316: 216720 + 688 = 217408
Step 317: 217408 + 688 = 218096
Step 318: 218096 + 688 = 218784
Step 319: 218784 + 688 = 219472
Step 320: 219472 + 688 = 220160
Step 321: 220160 + 688 = 220848
Step 322: 220848 + 688 = 221536
Step 323: 221536 + 688 = 222224
Step 324: 222224 + 688 = 222912
Step 325: 222912 + 688 = 223600
Step 326: 223600 + 688 = 224288
Step 327: 224288 + 688 = 224976
Step 328: 224976 + 688 = 225664
Step 329: 225664 + 688 = 226352
Step 330: 226352 + 688 = 227040
Step 331: 227040 + 688 = 227728
Step 332: 227728 + 688 = 228416
Step 333: 228416 + 688 = 229104
Step 334: 229104 + 688 = 229792
Step 335: 229792 + 688 = 230480
Step 336: 230480 + 688 = 231168
Step 337: 231168 + 688 = 231856
Step 338: 231856 + 688 = 232544
Step 339: 232544 + 688 = 233232
Step 340: 233232 + 688 = 233920
Step 341: 233920 + 688 = 234608
Step 342: 234608 + 688 = 235296
Step 343: 235296 + 688 = 235984
Step 344: 235984 + 688 = 236672
Step 345: 236672 + 688 = 237360
Step 346: 237360 + 688 = 238048
Step 347: 238048 + 688 = 238736
Step 348: 238736 + 688 = 239424
Step 349: 239424 + 688 = 240112
Step 350: 240112 + 688 = 240800
Step 351: 240800 + 688 = 241488
Step 352: 241488 + 688 = 242176
Step 353: 242176 + 688 = 242864
Step 354: 242864 + 688 = 243552
Step 355: 243552 + 688 = 244240
Step 356: 244240 + 688 = 244928
Step 357: 244928 + 688 = 245616
Step 358: 245616 + 688 = 246304
Step 359: 246304 + 688 = 246992
Step 360: 246992 + 688 = 247680
Step 361: 247680 + 688 = 248368
Step 362: 248368 + 688 = 249056
Step 363: 249056 + 688 = 249744
Step 364: 249744 + 688 = 250432
Step 365: 250432 + 688 = 251120
Step 366: 251120 + 688 = 251808
Step 367: 251808 + 688 = 252496
Step 368: 252496 + 688 = 253184
Step 369: 253184 + 688 = 253872
Step 370: 253872 + 688 = 254560
Step 371: 254560 + 688 = 255248
Step 372: 255248 + 688 = 255936
Step 373: 255936 + 688 = 256624
Step 374: 256624 + 688 = 257312
Step 375: 257312 + 688 = 258000
Step 376: 258000 + 688 = 258688
Step 377: 258688 + 688 = 259376
Step 378: 259376 + 688 = 260064
Step 379: 260064 + 688 = 260752
Step 380: 260752 + 688 = 261440
Step 381: 261440 + 688 = 262128
Step 382: 262128 + 688 = 262816
Step 383: 262816 + 688 = 263504
Step 384: 263504 + 688 = 264192
Step 385: 264192 + 688 = 264880
Step 386: 264880 + 688 = 265568
Step 387: 265568 + 688 = 266256
Step 388: 266256 + 688 = 266944
Step 389: 266944 + 688 = 267632
Step 390: 267632 + 688 = 268320
Step 391: 268320 + 688 = 269008
Step 392: 269008 + 688 = 269696
Step 393: 269696 + 688 = 270384
Step 394: 270384 + 688 = 271072
Step 395: 271072 + 688 = 271760
Step 396: 271760 + 688 = 272448
Step 397: 272448 + 688 = 273136
Step 398: 273136 + 688 = 273824
Step 399: 273824 + 688 = 274512
Step 400: 274512 + 688 = 275200
Step 401: 275200 + 688 = 275888
Step 402: 275888 + 688 = 276576
Step 403: 276576 + 688 = 277264
Step 404: 277264 + 688 = 277952
Step 405: 277952 + 688 = 278640
Step 406: 278640 + 688 = 279328
Step 407: 279328 + 688 = 280016
Step 408: 280016 + 688 = 280704
Step 409: 280704 + 688 = 281392
Step 410: 281392 + 688 = 282080
Step 411: 282080 + 688 = 282768
Step 412: 282768 + 688 = 283456
Step 413: 283456 + 688 = 284144
Step 414: 284144 + 688 = 284832
Step 415: 284832 + 688 = 285520
Step 416: 285520 + 688 = 286208
Step 417: 286208 + 688 = 286896
Step 418: 286896 + 688 = 287584
Step 419: 287584 + 688 = 288272
Step 420: 288272 + 688 = 288960
Step 421: 288960 + 688 = 289648
Step 422: 289648 + 688 = 290336
Step 423: 290336 + 688 = 291024
Step 424: 291024 + 688 = 291712
Step 425: 291712 + 688 = 292400
Step 426: 292400 + 688 = 293088
Step 427: 293088 + 688 = 293776
Step 428: 293776 + 688 = 294464
Step 429: 294464 + 688 = 295152
Step 430: 295152 + 688 = 295840
Step 431: 295840 + 688 = 296528
Step 432: 296528 + 688 = 297216
Step 433: 297216 + 688 = 297904
Step 434: 297904 + 688 = 298592
Step 435: 298592 + 688 = 299280
Step 436: 299280 + 688 = 299968
Step 437: 299968 + 688 = 300656
Step 438: 300656 + 688 = 301344
Step 439: 301344 + 688 = 302032
Step 440: 302032 + 688 = 302720
Step 441: 302720 + 688 = 303408
Step 442: 303408 + 688 = 304096
Step 443: 304096 + 688 = 304784
Step 444: 304784 + 688 = 305472
Step 445: 305472 + 688 = 306160
Step 446: 306160 + 688 = 306848
Step 447: 306848 + 688 = 307536
Step 448: 307536 + 688 = 308224
Step 449: 308224 + 688 = 308912
Step 450: 308912 + 688 = 309600
Step 451: 309600 + 688 = 310288
Step 452: 310288 + 688 = 310976
Step 453: 310976 + 688 = 311664
Step 454: 311664 + 688 = 312352
Step 455: 312352 + 688 = 313040
Step 456: 313040 + 688 = 313728

So, 688*456 = 313728