Alright, let's solve this math problem step by step. First, we have the number 640. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 416. So, we're going to take the number 640 and add it to itself 416 times.
Step 1: 0 + 640 = 640
Step 2: 640 + 640 = 1280
Step 3: 1280 + 640 = 1920
Step 4: 1920 + 640 = 2560
Step 5: 2560 + 640 = 3200
Step 6: 3200 + 640 = 3840
Step 7: 3840 + 640 = 4480
Step 8: 4480 + 640 = 5120
Step 9: 5120 + 640 = 5760
Step 10: 5760 + 640 = 6400
Step 11: 6400 + 640 = 7040
Step 12: 7040 + 640 = 7680
Step 13: 7680 + 640 = 8320
Step 14: 8320 + 640 = 8960
Step 15: 8960 + 640 = 9600
Step 16: 9600 + 640 = 10240
Step 17: 10240 + 640 = 10880
Step 18: 10880 + 640 = 11520
Step 19: 11520 + 640 = 12160
Step 20: 12160 + 640 = 12800
Step 21: 12800 + 640 = 13440
Step 22: 13440 + 640 = 14080
Step 23: 14080 + 640 = 14720
Step 24: 14720 + 640 = 15360
Step 25: 15360 + 640 = 16000
Step 26: 16000 + 640 = 16640
Step 27: 16640 + 640 = 17280
Step 28: 17280 + 640 = 17920
Step 29: 17920 + 640 = 18560
Step 30: 18560 + 640 = 19200
Step 31: 19200 + 640 = 19840
Step 32: 19840 + 640 = 20480
Step 33: 20480 + 640 = 21120
Step 34: 21120 + 640 = 21760
Step 35: 21760 + 640 = 22400
Step 36: 22400 + 640 = 23040
Step 37: 23040 + 640 = 23680
Step 38: 23680 + 640 = 24320
Step 39: 24320 + 640 = 24960
Step 40: 24960 + 640 = 25600
Step 41: 25600 + 640 = 26240
Step 42: 26240 + 640 = 26880
Step 43: 26880 + 640 = 27520
Step 44: 27520 + 640 = 28160
Step 45: 28160 + 640 = 28800
Step 46: 28800 + 640 = 29440
Step 47: 29440 + 640 = 30080
Step 48: 30080 + 640 = 30720
Step 49: 30720 + 640 = 31360
Step 50: 31360 + 640 = 32000
Step 51: 32000 + 640 = 32640
Step 52: 32640 + 640 = 33280
Step 53: 33280 + 640 = 33920
Step 54: 33920 + 640 = 34560
Step 55: 34560 + 640 = 35200
Step 56: 35200 + 640 = 35840
Step 57: 35840 + 640 = 36480
Step 58: 36480 + 640 = 37120
Step 59: 37120 + 640 = 37760
Step 60: 37760 + 640 = 38400
Step 61: 38400 + 640 = 39040
Step 62: 39040 + 640 = 39680
Step 63: 39680 + 640 = 40320
Step 64: 40320 + 640 = 40960
Step 65: 40960 + 640 = 41600
Step 66: 41600 + 640 = 42240
Step 67: 42240 + 640 = 42880
Step 68: 42880 + 640 = 43520
Step 69: 43520 + 640 = 44160
Step 70: 44160 + 640 = 44800
Step 71: 44800 + 640 = 45440
Step 72: 45440 + 640 = 46080
Step 73: 46080 + 640 = 46720
Step 74: 46720 + 640 = 47360
Step 75: 47360 + 640 = 48000
Step 76: 48000 + 640 = 48640
Step 77: 48640 + 640 = 49280
Step 78: 49280 + 640 = 49920
Step 79: 49920 + 640 = 50560
Step 80: 50560 + 640 = 51200
Step 81: 51200 + 640 = 51840
Step 82: 51840 + 640 = 52480
Step 83: 52480 + 640 = 53120
Step 84: 53120 + 640 = 53760
Step 85: 53760 + 640 = 54400
Step 86: 54400 + 640 = 55040
Step 87: 55040 + 640 = 55680
Step 88: 55680 + 640 = 56320
Step 89: 56320 + 640 = 56960
Step 90: 56960 + 640 = 57600
Step 91: 57600 + 640 = 58240
Step 92: 58240 + 640 = 58880
Step 93: 58880 + 640 = 59520
Step 94: 59520 + 640 = 60160
Step 95: 60160 + 640 = 60800
Step 96: 60800 + 640 = 61440
Step 97: 61440 + 640 = 62080
Step 98: 62080 + 640 = 62720
Step 99: 62720 + 640 = 63360
Step 100: 63360 + 640 = 64000
Step 101: 64000 + 640 = 64640
Step 102: 64640 + 640 = 65280
Step 103: 65280 + 640 = 65920
Step 104: 65920 + 640 = 66560
Step 105: 66560 + 640 = 67200
Step 106: 67200 + 640 = 67840
Step 107: 67840 + 640 = 68480
Step 108: 68480 + 640 = 69120
Step 109: 69120 + 640 = 69760
Step 110: 69760 + 640 = 70400
Step 111: 70400 + 640 = 71040
Step 112: 71040 + 640 = 71680
Step 113: 71680 + 640 = 72320
Step 114: 72320 + 640 = 72960
Step 115: 72960 + 640 = 73600
Step 116: 73600 + 640 = 74240
Step 117: 74240 + 640 = 74880
Step 118: 74880 + 640 = 75520
Step 119: 75520 + 640 = 76160
Step 120: 76160 + 640 = 76800
Step 121: 76800 + 640 = 77440
Step 122: 77440 + 640 = 78080
Step 123: 78080 + 640 = 78720
Step 124: 78720 + 640 = 79360
Step 125: 79360 + 640 = 80000
Step 126: 80000 + 640 = 80640
Step 127: 80640 + 640 = 81280
Step 128: 81280 + 640 = 81920
Step 129: 81920 + 640 = 82560
Step 130: 82560 + 640 = 83200
Step 131: 83200 + 640 = 83840
Step 132: 83840 + 640 = 84480
Step 133: 84480 + 640 = 85120
Step 134: 85120 + 640 = 85760
Step 135: 85760 + 640 = 86400
Step 136: 86400 + 640 = 87040
Step 137: 87040 + 640 = 87680
Step 138: 87680 + 640 = 88320
Step 139: 88320 + 640 = 88960
Step 140: 88960 + 640 = 89600
Step 141: 89600 + 640 = 90240
Step 142: 90240 + 640 = 90880
Step 143: 90880 + 640 = 91520
Step 144: 91520 + 640 = 92160
Step 145: 92160 + 640 = 92800
Step 146: 92800 + 640 = 93440
Step 147: 93440 + 640 = 94080
Step 148: 94080 + 640 = 94720
Step 149: 94720 + 640 = 95360
Step 150: 95360 + 640 = 96000
Step 151: 96000 + 640 = 96640
Step 152: 96640 + 640 = 97280
Step 153: 97280 + 640 = 97920
Step 154: 97920 + 640 = 98560
Step 155: 98560 + 640 = 99200
Step 156: 99200 + 640 = 99840
Step 157: 99840 + 640 = 100480
Step 158: 100480 + 640 = 101120
Step 159: 101120 + 640 = 101760
Step 160: 101760 + 640 = 102400
Step 161: 102400 + 640 = 103040
Step 162: 103040 + 640 = 103680
Step 163: 103680 + 640 = 104320
Step 164: 104320 + 640 = 104960
Step 165: 104960 + 640 = 105600
Step 166: 105600 + 640 = 106240
Step 167: 106240 + 640 = 106880
Step 168: 106880 + 640 = 107520
Step 169: 107520 + 640 = 108160
Step 170: 108160 + 640 = 108800
Step 171: 108800 + 640 = 109440
Step 172: 109440 + 640 = 110080
Step 173: 110080 + 640 = 110720
Step 174: 110720 + 640 = 111360
Step 175: 111360 + 640 = 112000
Step 176: 112000 + 640 = 112640
Step 177: 112640 + 640 = 113280
Step 178: 113280 + 640 = 113920
Step 179: 113920 + 640 = 114560
Step 180: 114560 + 640 = 115200
Step 181: 115200 + 640 = 115840
Step 182: 115840 + 640 = 116480
Step 183: 116480 + 640 = 117120
Step 184: 117120 + 640 = 117760
Step 185: 117760 + 640 = 118400
Step 186: 118400 + 640 = 119040
Step 187: 119040 + 640 = 119680
Step 188: 119680 + 640 = 120320
Step 189: 120320 + 640 = 120960
Step 190: 120960 + 640 = 121600
Step 191: 121600 + 640 = 122240
Step 192: 122240 + 640 = 122880
Step 193: 122880 + 640 = 123520
Step 194: 123520 + 640 = 124160
Step 195: 124160 + 640 = 124800
Step 196: 124800 + 640 = 125440
Step 197: 125440 + 640 = 126080
Step 198: 126080 + 640 = 126720
Step 199: 126720 + 640 = 127360
Step 200: 127360 + 640 = 128000
Step 201: 128000 + 640 = 128640
Step 202: 128640 + 640 = 129280
Step 203: 129280 + 640 = 129920
Step 204: 129920 + 640 = 130560
Step 205: 130560 + 640 = 131200
Step 206: 131200 + 640 = 131840
Step 207: 131840 + 640 = 132480
Step 208: 132480 + 640 = 133120
Step 209: 133120 + 640 = 133760
Step 210: 133760 + 640 = 134400
Step 211: 134400 + 640 = 135040
Step 212: 135040 + 640 = 135680
Step 213: 135680 + 640 = 136320
Step 214: 136320 + 640 = 136960
Step 215: 136960 + 640 = 137600
Step 216: 137600 + 640 = 138240
Step 217: 138240 + 640 = 138880
Step 218: 138880 + 640 = 139520
Step 219: 139520 + 640 = 140160
Step 220: 140160 + 640 = 140800
Step 221: 140800 + 640 = 141440
Step 222: 141440 + 640 = 142080
Step 223: 142080 + 640 = 142720
Step 224: 142720 + 640 = 143360
Step 225: 143360 + 640 = 144000
Step 226: 144000 + 640 = 144640
Step 227: 144640 + 640 = 145280
Step 228: 145280 + 640 = 145920
Step 229: 145920 + 640 = 146560
Step 230: 146560 + 640 = 147200
Step 231: 147200 + 640 = 147840
Step 232: 147840 + 640 = 148480
Step 233: 148480 + 640 = 149120
Step 234: 149120 + 640 = 149760
Step 235: 149760 + 640 = 150400
Step 236: 150400 + 640 = 151040
Step 237: 151040 + 640 = 151680
Step 238: 151680 + 640 = 152320
Step 239: 152320 + 640 = 152960
Step 240: 152960 + 640 = 153600
Step 241: 153600 + 640 = 154240
Step 242: 154240 + 640 = 154880
Step 243: 154880 + 640 = 155520
Step 244: 155520 + 640 = 156160
Step 245: 156160 + 640 = 156800
Step 246: 156800 + 640 = 157440
Step 247: 157440 + 640 = 158080
Step 248: 158080 + 640 = 158720
Step 249: 158720 + 640 = 159360
Step 250: 159360 + 640 = 160000
Step 251: 160000 + 640 = 160640
Step 252: 160640 + 640 = 161280
Step 253: 161280 + 640 = 161920
Step 254: 161920 + 640 = 162560
Step 255: 162560 + 640 = 163200
Step 256: 163200 + 640 = 163840
Step 257: 163840 + 640 = 164480
Step 258: 164480 + 640 = 165120
Step 259: 165120 + 640 = 165760
Step 260: 165760 + 640 = 166400
Step 261: 166400 + 640 = 167040
Step 262: 167040 + 640 = 167680
Step 263: 167680 + 640 = 168320
Step 264: 168320 + 640 = 168960
Step 265: 168960 + 640 = 169600
Step 266: 169600 + 640 = 170240
Step 267: 170240 + 640 = 170880
Step 268: 170880 + 640 = 171520
Step 269: 171520 + 640 = 172160
Step 270: 172160 + 640 = 172800
Step 271: 172800 + 640 = 173440
Step 272: 173440 + 640 = 174080
Step 273: 174080 + 640 = 174720
Step 274: 174720 + 640 = 175360
Step 275: 175360 + 640 = 176000
Step 276: 176000 + 640 = 176640
Step 277: 176640 + 640 = 177280
Step 278: 177280 + 640 = 177920
Step 279: 177920 + 640 = 178560
Step 280: 178560 + 640 = 179200
Step 281: 179200 + 640 = 179840
Step 282: 179840 + 640 = 180480
Step 283: 180480 + 640 = 181120
Step 284: 181120 + 640 = 181760
Step 285: 181760 + 640 = 182400
Step 286: 182400 + 640 = 183040
Step 287: 183040 + 640 = 183680
Step 288: 183680 + 640 = 184320
Step 289: 184320 + 640 = 184960
Step 290: 184960 + 640 = 185600
Step 291: 185600 + 640 = 186240
Step 292: 186240 + 640 = 186880
Step 293: 186880 + 640 = 187520
Step 294: 187520 + 640 = 188160
Step 295: 188160 + 640 = 188800
Step 296: 188800 + 640 = 189440
Step 297: 189440 + 640 = 190080
Step 298: 190080 + 640 = 190720
Step 299: 190720 + 640 = 191360
Step 300: 191360 + 640 = 192000
Step 301: 192000 + 640 = 192640
Step 302: 192640 + 640 = 193280
Step 303: 193280 + 640 = 193920
Step 304: 193920 + 640 = 194560
Step 305: 194560 + 640 = 195200
Step 306: 195200 + 640 = 195840
Step 307: 195840 + 640 = 196480
Step 308: 196480 + 640 = 197120
Step 309: 197120 + 640 = 197760
Step 310: 197760 + 640 = 198400
Step 311: 198400 + 640 = 199040
Step 312: 199040 + 640 = 199680
Step 313: 199680 + 640 = 200320
Step 314: 200320 + 640 = 200960
Step 315: 200960 + 640 = 201600
Step 316: 201600 + 640 = 202240
Step 317: 202240 + 640 = 202880
Step 318: 202880 + 640 = 203520
Step 319: 203520 + 640 = 204160
Step 320: 204160 + 640 = 204800
Step 321: 204800 + 640 = 205440
Step 322: 205440 + 640 = 206080
Step 323: 206080 + 640 = 206720
Step 324: 206720 + 640 = 207360
Step 325: 207360 + 640 = 208000
Step 326: 208000 + 640 = 208640
Step 327: 208640 + 640 = 209280
Step 328: 209280 + 640 = 209920
Step 329: 209920 + 640 = 210560
Step 330: 210560 + 640 = 211200
Step 331: 211200 + 640 = 211840
Step 332: 211840 + 640 = 212480
Step 333: 212480 + 640 = 213120
Step 334: 213120 + 640 = 213760
Step 335: 213760 + 640 = 214400
Step 336: 214400 + 640 = 215040
Step 337: 215040 + 640 = 215680
Step 338: 215680 + 640 = 216320
Step 339: 216320 + 640 = 216960
Step 340: 216960 + 640 = 217600
Step 341: 217600 + 640 = 218240
Step 342: 218240 + 640 = 218880
Step 343: 218880 + 640 = 219520
Step 344: 219520 + 640 = 220160
Step 345: 220160 + 640 = 220800
Step 346: 220800 + 640 = 221440
Step 347: 221440 + 640 = 222080
Step 348: 222080 + 640 = 222720
Step 349: 222720 + 640 = 223360
Step 350: 223360 + 640 = 224000
Step 351: 224000 + 640 = 224640
Step 352: 224640 + 640 = 225280
Step 353: 225280 + 640 = 225920
Step 354: 225920 + 640 = 226560
Step 355: 226560 + 640 = 227200
Step 356: 227200 + 640 = 227840
Step 357: 227840 + 640 = 228480
Step 358: 228480 + 640 = 229120
Step 359: 229120 + 640 = 229760
Step 360: 229760 + 640 = 230400
Step 361: 230400 + 640 = 231040
Step 362: 231040 + 640 = 231680
Step 363: 231680 + 640 = 232320
Step 364: 232320 + 640 = 232960
Step 365: 232960 + 640 = 233600
Step 366: 233600 + 640 = 234240
Step 367: 234240 + 640 = 234880
Step 368: 234880 + 640 = 235520
Step 369: 235520 + 640 = 236160
Step 370: 236160 + 640 = 236800
Step 371: 236800 + 640 = 237440
Step 372: 237440 + 640 = 238080
Step 373: 238080 + 640 = 238720
Step 374: 238720 + 640 = 239360
Step 375: 239360 + 640 = 240000
Step 376: 240000 + 640 = 240640
Step 377: 240640 + 640 = 241280
Step 378: 241280 + 640 = 241920
Step 379: 241920 + 640 = 242560
Step 380: 242560 + 640 = 243200
Step 381: 243200 + 640 = 243840
Step 382: 243840 + 640 = 244480
Step 383: 244480 + 640 = 245120
Step 384: 245120 + 640 = 245760
Step 385: 245760 + 640 = 246400
Step 386: 246400 + 640 = 247040
Step 387: 247040 + 640 = 247680
Step 388: 247680 + 640 = 248320
Step 389: 248320 + 640 = 248960
Step 390: 248960 + 640 = 249600
Step 391: 249600 + 640 = 250240
Step 392: 250240 + 640 = 250880
Step 393: 250880 + 640 = 251520
Step 394: 251520 + 640 = 252160
Step 395: 252160 + 640 = 252800
Step 396: 252800 + 640 = 253440
Step 397: 253440 + 640 = 254080
Step 398: 254080 + 640 = 254720
Step 399: 254720 + 640 = 255360
Step 400: 255360 + 640 = 256000
Step 401: 256000 + 640 = 256640
Step 402: 256640 + 640 = 257280
Step 403: 257280 + 640 = 257920
Step 404: 257920 + 640 = 258560
Step 405: 258560 + 640 = 259200
Step 406: 259200 + 640 = 259840
Step 407: 259840 + 640 = 260480
Step 408: 260480 + 640 = 261120
Step 409: 261120 + 640 = 261760
Step 410: 261760 + 640 = 262400
Step 411: 262400 + 640 = 263040
Step 412: 263040 + 640 = 263680
Step 413: 263680 + 640 = 264320
Step 414: 264320 + 640 = 264960
Step 415: 264960 + 640 = 265600
Step 416: 265600 + 640 = 266240

So, 640*416 = 266240