OK, let's work through this together. We're starting with 280 and we're going to multiply it by 407, which means we add 280 to itself 407 times.
Step 1: 0 + 280 = 280
Step 2: 280 + 280 = 560
Step 3: 560 + 280 = 840
Step 4: 840 + 280 = 1120
Step 5: 1120 + 280 = 1400
Step 6: 1400 + 280 = 1680
Step 7: 1680 + 280 = 1960
Step 8: 1960 + 280 = 2240
Step 9: 2240 + 280 = 2520
Step 10: 2520 + 280 = 2800
Step 11: 2800 + 280 = 3080
Step 12: 3080 + 280 = 3360
Step 13: 3360 + 280 = 3640
Step 14: 3640 + 280 = 3920
Step 15: 3920 + 280 = 4200
Step 16: 4200 + 280 = 4480
Step 17: 4480 + 280 = 4760
Step 18: 4760 + 280 = 5040
Step 19: 5040 + 280 = 5320
Step 20: 5320 + 280 = 5600
Step 21: 5600 + 280 = 5880
Step 22: 5880 + 280 = 6160
Step 23: 6160 + 280 = 6440
Step 24: 6440 + 280 = 6720
Step 25: 6720 + 280 = 7000
Step 26: 7000 + 280 = 7280
Step 27: 7280 + 280 = 7560
Step 28: 7560 + 280 = 7840
Step 29: 7840 + 280 = 8120
Step 30: 8120 + 280 = 8400
Step 31: 8400 + 280 = 8680
Step 32: 8680 + 280 = 8960
Step 33: 8960 + 280 = 9240
Step 34: 9240 + 280 = 9520
Step 35: 9520 + 280 = 9800
Step 36: 9800 + 280 = 10080
Step 37: 10080 + 280 = 10360
Step 38: 10360 + 280 = 10640
Step 39: 10640 + 280 = 10920
Step 40: 10920 + 280 = 11200
Step 41: 11200 + 280 = 11480
Step 42: 11480 + 280 = 11760
Step 43: 11760 + 280 = 12040
Step 44: 12040 + 280 = 12320
Step 45: 12320 + 280 = 12600
Step 46: 12600 + 280 = 12880
Step 47: 12880 + 280 = 13160
Step 48: 13160 + 280 = 13440
Step 49: 13440 + 280 = 13720
Step 50: 13720 + 280 = 14000
Step 51: 14000 + 280 = 14280
Step 52: 14280 + 280 = 14560
Step 53: 14560 + 280 = 14840
Step 54: 14840 + 280 = 15120
Step 55: 15120 + 280 = 15400
Step 56: 15400 + 280 = 15680
Step 57: 15680 + 280 = 15960
Step 58: 15960 + 280 = 16240
Step 59: 16240 + 280 = 16520
Step 60: 16520 + 280 = 16800
Step 61: 16800 + 280 = 17080
Step 62: 17080 + 280 = 17360
Step 63: 17360 + 280 = 17640
Step 64: 17640 + 280 = 17920
Step 65: 17920 + 280 = 18200
Step 66: 18200 + 280 = 18480
Step 67: 18480 + 280 = 18760
Step 68: 18760 + 280 = 19040
Step 69: 19040 + 280 = 19320
Step 70: 19320 + 280 = 19600
Step 71: 19600 + 280 = 19880
Step 72: 19880 + 280 = 20160
Step 73: 20160 + 280 = 20440
Step 74: 20440 + 280 = 20720
Step 75: 20720 + 280 = 21000
Step 76: 21000 + 280 = 21280
Step 77: 21280 + 280 = 21560
Step 78: 21560 + 280 = 21840
Step 79: 21840 + 280 = 22120
Step 80: 22120 + 280 = 22400
Step 81: 22400 + 280 = 22680
Step 82: 22680 + 280 = 22960
Step 83: 22960 + 280 = 23240
Step 84: 23240 + 280 = 23520
Step 85: 23520 + 280 = 23800
Step 86: 23800 + 280 = 24080
Step 87: 24080 + 280 = 24360
Step 88: 24360 + 280 = 24640
Step 89: 24640 + 280 = 24920
Step 90: 24920 + 280 = 25200
Step 91: 25200 + 280 = 25480
Step 92: 25480 + 280 = 25760
Step 93: 25760 + 280 = 26040
Step 94: 26040 + 280 = 26320
Step 95: 26320 + 280 = 26600
Step 96: 26600 + 280 = 26880
Step 97: 26880 + 280 = 27160
Step 98: 27160 + 280 = 27440
Step 99: 27440 + 280 = 27720
Step 100: 27720 + 280 = 28000
Step 101: 28000 + 280 = 28280
Step 102: 28280 + 280 = 28560
Step 103: 28560 + 280 = 28840
Step 104: 28840 + 280 = 29120
Step 105: 29120 + 280 = 29400
Step 106: 29400 + 280 = 29680
Step 107: 29680 + 280 = 29960
Step 108: 29960 + 280 = 30240
Step 109: 30240 + 280 = 30520
Step 110: 30520 + 280 = 30800
Step 111: 30800 + 280 = 31080
Step 112: 31080 + 280 = 31360
Step 113: 31360 + 280 = 31640
Step 114: 31640 + 280 = 31920
Step 115: 31920 + 280 = 32200
Step 116: 32200 + 280 = 32480
Step 117: 32480 + 280 = 32760
Step 118: 32760 + 280 = 33040
Step 119: 33040 + 280 = 33320
Step 120: 33320 + 280 = 33600
Step 121: 33600 + 280 = 33880
Step 122: 33880 + 280 = 34160
Step 123: 34160 + 280 = 34440
Step 124: 34440 + 280 = 34720
Step 125: 34720 + 280 = 35000
Step 126: 35000 + 280 = 35280
Step 127: 35280 + 280 = 35560
Step 128: 35560 + 280 = 35840
Step 129: 35840 + 280 = 36120
Step 130: 36120 + 280 = 36400
Step 131: 36400 + 280 = 36680
Step 132: 36680 + 280 = 36960
Step 133: 36960 + 280 = 37240
Step 134: 37240 + 280 = 37520
Step 135: 37520 + 280 = 37800
Step 136: 37800 + 280 = 38080
Step 137: 38080 + 280 = 38360
Step 138: 38360 + 280 = 38640
Step 139: 38640 + 280 = 38920
Step 140: 38920 + 280 = 39200
Step 141: 39200 + 280 = 39480
Step 142: 39480 + 280 = 39760
Step 143: 39760 + 280 = 40040
Step 144: 40040 + 280 = 40320
Step 145: 40320 + 280 = 40600
Step 146: 40600 + 280 = 40880
Step 147: 40880 + 280 = 41160
Step 148: 41160 + 280 = 41440
Step 149: 41440 + 280 = 41720
Step 150: 41720 + 280 = 42000
Step 151: 42000 + 280 = 42280
Step 152: 42280 + 280 = 42560
Step 153: 42560 + 280 = 42840
Step 154: 42840 + 280 = 43120
Step 155: 43120 + 280 = 43400
Step 156: 43400 + 280 = 43680
Step 157: 43680 + 280 = 43960
Step 158: 43960 + 280 = 44240
Step 159: 44240 + 280 = 44520
Step 160: 44520 + 280 = 44800
Step 161: 44800 + 280 = 45080
Step 162: 45080 + 280 = 45360
Step 163: 45360 + 280 = 45640
Step 164: 45640 + 280 = 45920
Step 165: 45920 + 280 = 46200
Step 166: 46200 + 280 = 46480
Step 167: 46480 + 280 = 46760
Step 168: 46760 + 280 = 47040
Step 169: 47040 + 280 = 47320
Step 170: 47320 + 280 = 47600
Step 171: 47600 + 280 = 47880
Step 172: 47880 + 280 = 48160
Step 173: 48160 + 280 = 48440
Step 174: 48440 + 280 = 48720
Step 175: 48720 + 280 = 49000
Step 176: 49000 + 280 = 49280
Step 177: 49280 + 280 = 49560
Step 178: 49560 + 280 = 49840
Step 179: 49840 + 280 = 50120
Step 180: 50120 + 280 = 50400
Step 181: 50400 + 280 = 50680
Step 182: 50680 + 280 = 50960
Step 183: 50960 + 280 = 51240
Step 184: 51240 + 280 = 51520
Step 185: 51520 + 280 = 51800
Step 186: 51800 + 280 = 52080
Step 187: 52080 + 280 = 52360
Step 188: 52360 + 280 = 52640
Step 189: 52640 + 280 = 52920
Step 190: 52920 + 280 = 53200
Step 191: 53200 + 280 = 53480
Step 192: 53480 + 280 = 53760
Step 193: 53760 + 280 = 54040
Step 194: 54040 + 280 = 54320
Step 195: 54320 + 280 = 54600
Step 196: 54600 + 280 = 54880
Step 197: 54880 + 280 = 55160
Step 198: 55160 + 280 = 55440
Step 199: 55440 + 280 = 55720
Step 200: 55720 + 280 = 56000
Step 201: 56000 + 280 = 56280
Step 202: 56280 + 280 = 56560
Step 203: 56560 + 280 = 56840
Step 204: 56840 + 280 = 57120
Step 205: 57120 + 280 = 57400
Step 206: 57400 + 280 = 57680
Step 207: 57680 + 280 = 57960
Step 208: 57960 + 280 = 58240
Step 209: 58240 + 280 = 58520
Step 210: 58520 + 280 = 58800
Step 211: 58800 + 280 = 59080
Step 212: 59080 + 280 = 59360
Step 213: 59360 + 280 = 59640
Step 214: 59640 + 280 = 59920
Step 215: 59920 + 280 = 60200
Step 216: 60200 + 280 = 60480
Step 217: 60480 + 280 = 60760
Step 218: 60760 + 280 = 61040
Step 219: 61040 + 280 = 61320
Step 220: 61320 + 280 = 61600
Step 221: 61600 + 280 = 61880
Step 222: 61880 + 280 = 62160
Step 223: 62160 + 280 = 62440
Step 224: 62440 + 280 = 62720
Step 225: 62720 + 280 = 63000
Step 226: 63000 + 280 = 63280
Step 227: 63280 + 280 = 63560
Step 228: 63560 + 280 = 63840
Step 229: 63840 + 280 = 64120
Step 230: 64120 + 280 = 64400
Step 231: 64400 + 280 = 64680
Step 232: 64680 + 280 = 64960
Step 233: 64960 + 280 = 65240
Step 234: 65240 + 280 = 65520
Step 235: 65520 + 280 = 65800
Step 236: 65800 + 280 = 66080
Step 237: 66080 + 280 = 66360
Step 238: 66360 + 280 = 66640
Step 239: 66640 + 280 = 66920
Step 240: 66920 + 280 = 67200
Step 241: 67200 + 280 = 67480
Step 242: 67480 + 280 = 67760
Step 243: 67760 + 280 = 68040
Step 244: 68040 + 280 = 68320
Step 245: 68320 + 280 = 68600
Step 246: 68600 + 280 = 68880
Step 247: 68880 + 280 = 69160
Step 248: 69160 + 280 = 69440
Step 249: 69440 + 280 = 69720
Step 250: 69720 + 280 = 70000
Step 251: 70000 + 280 = 70280
Step 252: 70280 + 280 = 70560
Step 253: 70560 + 280 = 70840
Step 254: 70840 + 280 = 71120
Step 255: 71120 + 280 = 71400
Step 256: 71400 + 280 = 71680
Step 257: 71680 + 280 = 71960
Step 258: 71960 + 280 = 72240
Step 259: 72240 + 280 = 72520
Step 260: 72520 + 280 = 72800
Step 261: 72800 + 280 = 73080
Step 262: 73080 + 280 = 73360
Step 263: 73360 + 280 = 73640
Step 264: 73640 + 280 = 73920
Step 265: 73920 + 280 = 74200
Step 266: 74200 + 280 = 74480
Step 267: 74480 + 280 = 74760
Step 268: 74760 + 280 = 75040
Step 269: 75040 + 280 = 75320
Step 270: 75320 + 280 = 75600
Step 271: 75600 + 280 = 75880
Step 272: 75880 + 280 = 76160
Step 273: 76160 + 280 = 76440
Step 274: 76440 + 280 = 76720
Step 275: 76720 + 280 = 77000
Step 276: 77000 + 280 = 77280
Step 277: 77280 + 280 = 77560
Step 278: 77560 + 280 = 77840
Step 279: 77840 + 280 = 78120
Step 280: 78120 + 280 = 78400
Step 281: 78400 + 280 = 78680
Step 282: 78680 + 280 = 78960
Step 283: 78960 + 280 = 79240
Step 284: 79240 + 280 = 79520
Step 285: 79520 + 280 = 79800
Step 286: 79800 + 280 = 80080
Step 287: 80080 + 280 = 80360
Step 288: 80360 + 280 = 80640
Step 289: 80640 + 280 = 80920
Step 290: 80920 + 280 = 81200
Step 291: 81200 + 280 = 81480
Step 292: 81480 + 280 = 81760
Step 293: 81760 + 280 = 82040
Step 294: 82040 + 280 = 82320
Step 295: 82320 + 280 = 82600
Step 296: 82600 + 280 = 82880
Step 297: 82880 + 280 = 83160
Step 298: 83160 + 280 = 83440
Step 299: 83440 + 280 = 83720
Step 300: 83720 + 280 = 84000
Step 301: 84000 + 280 = 84280
Step 302: 84280 + 280 = 84560
Step 303: 84560 + 280 = 84840
Step 304: 84840 + 280 = 85120
Step 305: 85120 + 280 = 85400
Step 306: 85400 + 280 = 85680
Step 307: 85680 + 280 = 85960
Step 308: 85960 + 280 = 86240
Step 309: 86240 + 280 = 86520
Step 310: 86520 + 280 = 86800
Step 311: 86800 + 280 = 87080
Step 312: 87080 + 280 = 87360
Step 313: 87360 + 280 = 87640
Step 314: 87640 + 280 = 87920
Step 315: 87920 + 280 = 88200
Step 316: 88200 + 280 = 88480
Step 317: 88480 + 280 = 88760
Step 318: 88760 + 280 = 89040
Step 319: 89040 + 280 = 89320
Step 320: 89320 + 280 = 89600
Step 321: 89600 + 280 = 89880
Step 322: 89880 + 280 = 90160
Step 323: 90160 + 280 = 90440
Step 324: 90440 + 280 = 90720
Step 325: 90720 + 280 = 91000
Step 326: 91000 + 280 = 91280
Step 327: 91280 + 280 = 91560
Step 328: 91560 + 280 = 91840
Step 329: 91840 + 280 = 92120
Step 330: 92120 + 280 = 92400
Step 331: 92400 + 280 = 92680
Step 332: 92680 + 280 = 92960
Step 333: 92960 + 280 = 93240
Step 334: 93240 + 280 = 93520
Step 335: 93520 + 280 = 93800
Step 336: 93800 + 280 = 94080
Step 337: 94080 + 280 = 94360
Step 338: 94360 + 280 = 94640
Step 339: 94640 + 280 = 94920
Step 340: 94920 + 280 = 95200
Step 341: 95200 + 280 = 95480
Step 342: 95480 + 280 = 95760
Step 343: 95760 + 280 = 96040
Step 344: 96040 + 280 = 96320
Step 345: 96320 + 280 = 96600
Step 346: 96600 + 280 = 96880
Step 347: 96880 + 280 = 97160
Step 348: 97160 + 280 = 97440
Step 349: 97440 + 280 = 97720
Step 350: 97720 + 280 = 98000
Step 351: 98000 + 280 = 98280
Step 352: 98280 + 280 = 98560
Step 353: 98560 + 280 = 98840
Step 354: 98840 + 280 = 99120
Step 355: 99120 + 280 = 99400
Step 356: 99400 + 280 = 99680
Step 357: 99680 + 280 = 99960
Step 358: 99960 + 280 = 100240
Step 359: 100240 + 280 = 100520
Step 360: 100520 + 280 = 100800
Step 361: 100800 + 280 = 101080
Step 362: 101080 + 280 = 101360
Step 363: 101360 + 280 = 101640
Step 364: 101640 + 280 = 101920
Step 365: 101920 + 280 = 102200
Step 366: 102200 + 280 = 102480
Step 367: 102480 + 280 = 102760
Step 368: 102760 + 280 = 103040
Step 369: 103040 + 280 = 103320
Step 370: 103320 + 280 = 103600
Step 371: 103600 + 280 = 103880
Step 372: 103880 + 280 = 104160
Step 373: 104160 + 280 = 104440
Step 374: 104440 + 280 = 104720
Step 375: 104720 + 280 = 105000
Step 376: 105000 + 280 = 105280
Step 377: 105280 + 280 = 105560
Step 378: 105560 + 280 = 105840
Step 379: 105840 + 280 = 106120
Step 380: 106120 + 280 = 106400
Step 381: 106400 + 280 = 106680
Step 382: 106680 + 280 = 106960
Step 383: 106960 + 280 = 107240
Step 384: 107240 + 280 = 107520
Step 385: 107520 + 280 = 107800
Step 386: 107800 + 280 = 108080
Step 387: 108080 + 280 = 108360
Step 388: 108360 + 280 = 108640
Step 389: 108640 + 280 = 108920
Step 390: 108920 + 280 = 109200
Step 391: 109200 + 280 = 109480
Step 392: 109480 + 280 = 109760
Step 393: 109760 + 280 = 110040
Step 394: 110040 + 280 = 110320
Step 395: 110320 + 280 = 110600
Step 396: 110600 + 280 = 110880
Step 397: 110880 + 280 = 111160
Step 398: 111160 + 280 = 111440
Step 399: 111440 + 280 = 111720
Step 400: 111720 + 280 = 112000
Step 401: 112000 + 280 = 112280
Step 402: 112280 + 280 = 112560
Step 403: 112560 + 280 = 112840
Step 404: 112840 + 280 = 113120
Step 405: 113120 + 280 = 113400
Step 406: 113400 + 280 = 113680
Step 407: 113680 + 280 = 113960

So, 280*407 = 113960