Alright, let's solve this math problem step by step. First, we have the number 420. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 424. So, we're going to take the number 420 and add it to itself 424 times.
Step 1: 0 + 420 = 420
Step 2: 420 + 420 = 840
Step 3: 840 + 420 = 1260
Step 4: 1260 + 420 = 1680
Step 5: 1680 + 420 = 2100
Step 6: 2100 + 420 = 2520
Step 7: 2520 + 420 = 2940
Step 8: 2940 + 420 = 3360
Step 9: 3360 + 420 = 3780
Step 10: 3780 + 420 = 4200
Step 11: 4200 + 420 = 4620
Step 12: 4620 + 420 = 5040
Step 13: 5040 + 420 = 5460
Step 14: 5460 + 420 = 5880
Step 15: 5880 + 420 = 6300
Step 16: 6300 + 420 = 6720
Step 17: 6720 + 420 = 7140
Step 18: 7140 + 420 = 7560
Step 19: 7560 + 420 = 7980
Step 20: 7980 + 420 = 8400
Step 21: 8400 + 420 = 8820
Step 22: 8820 + 420 = 9240
Step 23: 9240 + 420 = 9660
Step 24: 9660 + 420 = 10080
Step 25: 10080 + 420 = 10500
Step 26: 10500 + 420 = 10920
Step 27: 10920 + 420 = 11340
Step 28: 11340 + 420 = 11760
Step 29: 11760 + 420 = 12180
Step 30: 12180 + 420 = 12600
Step 31: 12600 + 420 = 13020
Step 32: 13020 + 420 = 13440
Step 33: 13440 + 420 = 13860
Step 34: 13860 + 420 = 14280
Step 35: 14280 + 420 = 14700
Step 36: 14700 + 420 = 15120
Step 37: 15120 + 420 = 15540
Step 38: 15540 + 420 = 15960
Step 39: 15960 + 420 = 16380
Step 40: 16380 + 420 = 16800
Step 41: 16800 + 420 = 17220
Step 42: 17220 + 420 = 17640
Step 43: 17640 + 420 = 18060
Step 44: 18060 + 420 = 18480
Step 45: 18480 + 420 = 18900
Step 46: 18900 + 420 = 19320
Step 47: 19320 + 420 = 19740
Step 48: 19740 + 420 = 20160
Step 49: 20160 + 420 = 20580
Step 50: 20580 + 420 = 21000
Step 51: 21000 + 420 = 21420
Step 52: 21420 + 420 = 21840
Step 53: 21840 + 420 = 22260
Step 54: 22260 + 420 = 22680
Step 55: 22680 + 420 = 23100
Step 56: 23100 + 420 = 23520
Step 57: 23520 + 420 = 23940
Step 58: 23940 + 420 = 24360
Step 59: 24360 + 420 = 24780
Step 60: 24780 + 420 = 25200
Step 61: 25200 + 420 = 25620
Step 62: 25620 + 420 = 26040
Step 63: 26040 + 420 = 26460
Step 64: 26460 + 420 = 26880
Step 65: 26880 + 420 = 27300
Step 66: 27300 + 420 = 27720
Step 67: 27720 + 420 = 28140
Step 68: 28140 + 420 = 28560
Step 69: 28560 + 420 = 28980
Step 70: 28980 + 420 = 29400
Step 71: 29400 + 420 = 29820
Step 72: 29820 + 420 = 30240
Step 73: 30240 + 420 = 30660
Step 74: 30660 + 420 = 31080
Step 75: 31080 + 420 = 31500
Step 76: 31500 + 420 = 31920
Step 77: 31920 + 420 = 32340
Step 78: 32340 + 420 = 32760
Step 79: 32760 + 420 = 33180
Step 80: 33180 + 420 = 33600
Step 81: 33600 + 420 = 34020
Step 82: 34020 + 420 = 34440
Step 83: 34440 + 420 = 34860
Step 84: 34860 + 420 = 35280
Step 85: 35280 + 420 = 35700
Step 86: 35700 + 420 = 36120
Step 87: 36120 + 420 = 36540
Step 88: 36540 + 420 = 36960
Step 89: 36960 + 420 = 37380
Step 90: 37380 + 420 = 37800
Step 91: 37800 + 420 = 38220
Step 92: 38220 + 420 = 38640
Step 93: 38640 + 420 = 39060
Step 94: 39060 + 420 = 39480
Step 95: 39480 + 420 = 39900
Step 96: 39900 + 420 = 40320
Step 97: 40320 + 420 = 40740
Step 98: 40740 + 420 = 41160
Step 99: 41160 + 420 = 41580
Step 100: 41580 + 420 = 42000
Step 101: 42000 + 420 = 42420
Step 102: 42420 + 420 = 42840
Step 103: 42840 + 420 = 43260
Step 104: 43260 + 420 = 43680
Step 105: 43680 + 420 = 44100
Step 106: 44100 + 420 = 44520
Step 107: 44520 + 420 = 44940
Step 108: 44940 + 420 = 45360
Step 109: 45360 + 420 = 45780
Step 110: 45780 + 420 = 46200
Step 111: 46200 + 420 = 46620
Step 112: 46620 + 420 = 47040
Step 113: 47040 + 420 = 47460
Step 114: 47460 + 420 = 47880
Step 115: 47880 + 420 = 48300
Step 116: 48300 + 420 = 48720
Step 117: 48720 + 420 = 49140
Step 118: 49140 + 420 = 49560
Step 119: 49560 + 420 = 49980
Step 120: 49980 + 420 = 50400
Step 121: 50400 + 420 = 50820
Step 122: 50820 + 420 = 51240
Step 123: 51240 + 420 = 51660
Step 124: 51660 + 420 = 52080
Step 125: 52080 + 420 = 52500
Step 126: 52500 + 420 = 52920
Step 127: 52920 + 420 = 53340
Step 128: 53340 + 420 = 53760
Step 129: 53760 + 420 = 54180
Step 130: 54180 + 420 = 54600
Step 131: 54600 + 420 = 55020
Step 132: 55020 + 420 = 55440
Step 133: 55440 + 420 = 55860
Step 134: 55860 + 420 = 56280
Step 135: 56280 + 420 = 56700
Step 136: 56700 + 420 = 57120
Step 137: 57120 + 420 = 57540
Step 138: 57540 + 420 = 57960
Step 139: 57960 + 420 = 58380
Step 140: 58380 + 420 = 58800
Step 141: 58800 + 420 = 59220
Step 142: 59220 + 420 = 59640
Step 143: 59640 + 420 = 60060
Step 144: 60060 + 420 = 60480
Step 145: 60480 + 420 = 60900
Step 146: 60900 + 420 = 61320
Step 147: 61320 + 420 = 61740
Step 148: 61740 + 420 = 62160
Step 149: 62160 + 420 = 62580
Step 150: 62580 + 420 = 63000
Step 151: 63000 + 420 = 63420
Step 152: 63420 + 420 = 63840
Step 153: 63840 + 420 = 64260
Step 154: 64260 + 420 = 64680
Step 155: 64680 + 420 = 65100
Step 156: 65100 + 420 = 65520
Step 157: 65520 + 420 = 65940
Step 158: 65940 + 420 = 66360
Step 159: 66360 + 420 = 66780
Step 160: 66780 + 420 = 67200
Step 161: 67200 + 420 = 67620
Step 162: 67620 + 420 = 68040
Step 163: 68040 + 420 = 68460
Step 164: 68460 + 420 = 68880
Step 165: 68880 + 420 = 69300
Step 166: 69300 + 420 = 69720
Step 167: 69720 + 420 = 70140
Step 168: 70140 + 420 = 70560
Step 169: 70560 + 420 = 70980
Step 170: 70980 + 420 = 71400
Step 171: 71400 + 420 = 71820
Step 172: 71820 + 420 = 72240
Step 173: 72240 + 420 = 72660
Step 174: 72660 + 420 = 73080
Step 175: 73080 + 420 = 73500
Step 176: 73500 + 420 = 73920
Step 177: 73920 + 420 = 74340
Step 178: 74340 + 420 = 74760
Step 179: 74760 + 420 = 75180
Step 180: 75180 + 420 = 75600
Step 181: 75600 + 420 = 76020
Step 182: 76020 + 420 = 76440
Step 183: 76440 + 420 = 76860
Step 184: 76860 + 420 = 77280
Step 185: 77280 + 420 = 77700
Step 186: 77700 + 420 = 78120
Step 187: 78120 + 420 = 78540
Step 188: 78540 + 420 = 78960
Step 189: 78960 + 420 = 79380
Step 190: 79380 + 420 = 79800
Step 191: 79800 + 420 = 80220
Step 192: 80220 + 420 = 80640
Step 193: 80640 + 420 = 81060
Step 194: 81060 + 420 = 81480
Step 195: 81480 + 420 = 81900
Step 196: 81900 + 420 = 82320
Step 197: 82320 + 420 = 82740
Step 198: 82740 + 420 = 83160
Step 199: 83160 + 420 = 83580
Step 200: 83580 + 420 = 84000
Step 201: 84000 + 420 = 84420
Step 202: 84420 + 420 = 84840
Step 203: 84840 + 420 = 85260
Step 204: 85260 + 420 = 85680
Step 205: 85680 + 420 = 86100
Step 206: 86100 + 420 = 86520
Step 207: 86520 + 420 = 86940
Step 208: 86940 + 420 = 87360
Step 209: 87360 + 420 = 87780
Step 210: 87780 + 420 = 88200
Step 211: 88200 + 420 = 88620
Step 212: 88620 + 420 = 89040
Step 213: 89040 + 420 = 89460
Step 214: 89460 + 420 = 89880
Step 215: 89880 + 420 = 90300
Step 216: 90300 + 420 = 90720
Step 217: 90720 + 420 = 91140
Step 218: 91140 + 420 = 91560
Step 219: 91560 + 420 = 91980
Step 220: 91980 + 420 = 92400
Step 221: 92400 + 420 = 92820
Step 222: 92820 + 420 = 93240
Step 223: 93240 + 420 = 93660
Step 224: 93660 + 420 = 94080
Step 225: 94080 + 420 = 94500
Step 226: 94500 + 420 = 94920
Step 227: 94920 + 420 = 95340
Step 228: 95340 + 420 = 95760
Step 229: 95760 + 420 = 96180
Step 230: 96180 + 420 = 96600
Step 231: 96600 + 420 = 97020
Step 232: 97020 + 420 = 97440
Step 233: 97440 + 420 = 97860
Step 234: 97860 + 420 = 98280
Step 235: 98280 + 420 = 98700
Step 236: 98700 + 420 = 99120
Step 237: 99120 + 420 = 99540
Step 238: 99540 + 420 = 99960
Step 239: 99960 + 420 = 100380
Step 240: 100380 + 420 = 100800
Step 241: 100800 + 420 = 101220
Step 242: 101220 + 420 = 101640
Step 243: 101640 + 420 = 102060
Step 244: 102060 + 420 = 102480
Step 245: 102480 + 420 = 102900
Step 246: 102900 + 420 = 103320
Step 247: 103320 + 420 = 103740
Step 248: 103740 + 420 = 104160
Step 249: 104160 + 420 = 104580
Step 250: 104580 + 420 = 105000
Step 251: 105000 + 420 = 105420
Step 252: 105420 + 420 = 105840
Step 253: 105840 + 420 = 106260
Step 254: 106260 + 420 = 106680
Step 255: 106680 + 420 = 107100
Step 256: 107100 + 420 = 107520
Step 257: 107520 + 420 = 107940
Step 258: 107940 + 420 = 108360
Step 259: 108360 + 420 = 108780
Step 260: 108780 + 420 = 109200
Step 261: 109200 + 420 = 109620
Step 262: 109620 + 420 = 110040
Step 263: 110040 + 420 = 110460
Step 264: 110460 + 420 = 110880
Step 265: 110880 + 420 = 111300
Step 266: 111300 + 420 = 111720
Step 267: 111720 + 420 = 112140
Step 268: 112140 + 420 = 112560
Step 269: 112560 + 420 = 112980
Step 270: 112980 + 420 = 113400
Step 271: 113400 + 420 = 113820
Step 272: 113820 + 420 = 114240
Step 273: 114240 + 420 = 114660
Step 274: 114660 + 420 = 115080
Step 275: 115080 + 420 = 115500
Step 276: 115500 + 420 = 115920
Step 277: 115920 + 420 = 116340
Step 278: 116340 + 420 = 116760
Step 279: 116760 + 420 = 117180
Step 280: 117180 + 420 = 117600
Step 281: 117600 + 420 = 118020
Step 282: 118020 + 420 = 118440
Step 283: 118440 + 420 = 118860
Step 284: 118860 + 420 = 119280
Step 285: 119280 + 420 = 119700
Step 286: 119700 + 420 = 120120
Step 287: 120120 + 420 = 120540
Step 288: 120540 + 420 = 120960
Step 289: 120960 + 420 = 121380
Step 290: 121380 + 420 = 121800
Step 291: 121800 + 420 = 122220
Step 292: 122220 + 420 = 122640
Step 293: 122640 + 420 = 123060
Step 294: 123060 + 420 = 123480
Step 295: 123480 + 420 = 123900
Step 296: 123900 + 420 = 124320
Step 297: 124320 + 420 = 124740
Step 298: 124740 + 420 = 125160
Step 299: 125160 + 420 = 125580
Step 300: 125580 + 420 = 126000
Step 301: 126000 + 420 = 126420
Step 302: 126420 + 420 = 126840
Step 303: 126840 + 420 = 127260
Step 304: 127260 + 420 = 127680
Step 305: 127680 + 420 = 128100
Step 306: 128100 + 420 = 128520
Step 307: 128520 + 420 = 128940
Step 308: 128940 + 420 = 129360
Step 309: 129360 + 420 = 129780
Step 310: 129780 + 420 = 130200
Step 311: 130200 + 420 = 130620
Step 312: 130620 + 420 = 131040
Step 313: 131040 + 420 = 131460
Step 314: 131460 + 420 = 131880
Step 315: 131880 + 420 = 132300
Step 316: 132300 + 420 = 132720
Step 317: 132720 + 420 = 133140
Step 318: 133140 + 420 = 133560
Step 319: 133560 + 420 = 133980
Step 320: 133980 + 420 = 134400
Step 321: 134400 + 420 = 134820
Step 322: 134820 + 420 = 135240
Step 323: 135240 + 420 = 135660
Step 324: 135660 + 420 = 136080
Step 325: 136080 + 420 = 136500
Step 326: 136500 + 420 = 136920
Step 327: 136920 + 420 = 137340
Step 328: 137340 + 420 = 137760
Step 329: 137760 + 420 = 138180
Step 330: 138180 + 420 = 138600
Step 331: 138600 + 420 = 139020
Step 332: 139020 + 420 = 139440
Step 333: 139440 + 420 = 139860
Step 334: 139860 + 420 = 140280
Step 335: 140280 + 420 = 140700
Step 336: 140700 + 420 = 141120
Step 337: 141120 + 420 = 141540
Step 338: 141540 + 420 = 141960
Step 339: 141960 + 420 = 142380
Step 340: 142380 + 420 = 142800
Step 341: 142800 + 420 = 143220
Step 342: 143220 + 420 = 143640
Step 343: 143640 + 420 = 144060
Step 344: 144060 + 420 = 144480
Step 345: 144480 + 420 = 144900
Step 346: 144900 + 420 = 145320
Step 347: 145320 + 420 = 145740
Step 348: 145740 + 420 = 146160
Step 349: 146160 + 420 = 146580
Step 350: 146580 + 420 = 147000
Step 351: 147000 + 420 = 147420
Step 352: 147420 + 420 = 147840
Step 353: 147840 + 420 = 148260
Step 354: 148260 + 420 = 148680
Step 355: 148680 + 420 = 149100
Step 356: 149100 + 420 = 149520
Step 357: 149520 + 420 = 149940
Step 358: 149940 + 420 = 150360
Step 359: 150360 + 420 = 150780
Step 360: 150780 + 420 = 151200
Step 361: 151200 + 420 = 151620
Step 362: 151620 + 420 = 152040
Step 363: 152040 + 420 = 152460
Step 364: 152460 + 420 = 152880
Step 365: 152880 + 420 = 153300
Step 366: 153300 + 420 = 153720
Step 367: 153720 + 420 = 154140
Step 368: 154140 + 420 = 154560
Step 369: 154560 + 420 = 154980
Step 370: 154980 + 420 = 155400
Step 371: 155400 + 420 = 155820
Step 372: 155820 + 420 = 156240
Step 373: 156240 + 420 = 156660
Step 374: 156660 + 420 = 157080
Step 375: 157080 + 420 = 157500
Step 376: 157500 + 420 = 157920
Step 377: 157920 + 420 = 158340
Step 378: 158340 + 420 = 158760
Step 379: 158760 + 420 = 159180
Step 380: 159180 + 420 = 159600
Step 381: 159600 + 420 = 160020
Step 382: 160020 + 420 = 160440
Step 383: 160440 + 420 = 160860
Step 384: 160860 + 420 = 161280
Step 385: 161280 + 420 = 161700
Step 386: 161700 + 420 = 162120
Step 387: 162120 + 420 = 162540
Step 388: 162540 + 420 = 162960
Step 389: 162960 + 420 = 163380
Step 390: 163380 + 420 = 163800
Step 391: 163800 + 420 = 164220
Step 392: 164220 + 420 = 164640
Step 393: 164640 + 420 = 165060
Step 394: 165060 + 420 = 165480
Step 395: 165480 + 420 = 165900
Step 396: 165900 + 420 = 166320
Step 397: 166320 + 420 = 166740
Step 398: 166740 + 420 = 167160
Step 399: 167160 + 420 = 167580
Step 400: 167580 + 420 = 168000
Step 401: 168000 + 420 = 168420
Step 402: 168420 + 420 = 168840
Step 403: 168840 + 420 = 169260
Step 404: 169260 + 420 = 169680
Step 405: 169680 + 420 = 170100
Step 406: 170100 + 420 = 170520
Step 407: 170520 + 420 = 170940
Step 408: 170940 + 420 = 171360
Step 409: 171360 + 420 = 171780
Step 410: 171780 + 420 = 172200
Step 411: 172200 + 420 = 172620
Step 412: 172620 + 420 = 173040
Step 413: 173040 + 420 = 173460
Step 414: 173460 + 420 = 173880
Step 415: 173880 + 420 = 174300
Step 416: 174300 + 420 = 174720
Step 417: 174720 + 420 = 175140
Step 418: 175140 + 420 = 175560
Step 419: 175560 + 420 = 175980
Step 420: 175980 + 420 = 176400
Step 421: 176400 + 420 = 176820
Step 422: 176820 + 420 = 177240
Step 423: 177240 + 420 = 177660
Step 424: 177660 + 420 = 178080

So, 420*424 = 178080