Let's get this math done. We have 520 and we're going to multiply it by 320. This is the same as taking 520 and adding it to itself 320 times.
Step 1: 0 + 520 = 520
Step 2: 520 + 520 = 1040
Step 3: 1040 + 520 = 1560
Step 4: 1560 + 520 = 2080
Step 5: 2080 + 520 = 2600
Step 6: 2600 + 520 = 3120
Step 7: 3120 + 520 = 3640
Step 8: 3640 + 520 = 4160
Step 9: 4160 + 520 = 4680
Step 10: 4680 + 520 = 5200
Step 11: 5200 + 520 = 5720
Step 12: 5720 + 520 = 6240
Step 13: 6240 + 520 = 6760
Step 14: 6760 + 520 = 7280
Step 15: 7280 + 520 = 7800
Step 16: 7800 + 520 = 8320
Step 17: 8320 + 520 = 8840
Step 18: 8840 + 520 = 9360
Step 19: 9360 + 520 = 9880
Step 20: 9880 + 520 = 10400
Step 21: 10400 + 520 = 10920
Step 22: 10920 + 520 = 11440
Step 23: 11440 + 520 = 11960
Step 24: 11960 + 520 = 12480
Step 25: 12480 + 520 = 13000
Step 26: 13000 + 520 = 13520
Step 27: 13520 + 520 = 14040
Step 28: 14040 + 520 = 14560
Step 29: 14560 + 520 = 15080
Step 30: 15080 + 520 = 15600
Step 31: 15600 + 520 = 16120
Step 32: 16120 + 520 = 16640
Step 33: 16640 + 520 = 17160
Step 34: 17160 + 520 = 17680
Step 35: 17680 + 520 = 18200
Step 36: 18200 + 520 = 18720
Step 37: 18720 + 520 = 19240
Step 38: 19240 + 520 = 19760
Step 39: 19760 + 520 = 20280
Step 40: 20280 + 520 = 20800
Step 41: 20800 + 520 = 21320
Step 42: 21320 + 520 = 21840
Step 43: 21840 + 520 = 22360
Step 44: 22360 + 520 = 22880
Step 45: 22880 + 520 = 23400
Step 46: 23400 + 520 = 23920
Step 47: 23920 + 520 = 24440
Step 48: 24440 + 520 = 24960
Step 49: 24960 + 520 = 25480
Step 50: 25480 + 520 = 26000
Step 51: 26000 + 520 = 26520
Step 52: 26520 + 520 = 27040
Step 53: 27040 + 520 = 27560
Step 54: 27560 + 520 = 28080
Step 55: 28080 + 520 = 28600
Step 56: 28600 + 520 = 29120
Step 57: 29120 + 520 = 29640
Step 58: 29640 + 520 = 30160
Step 59: 30160 + 520 = 30680
Step 60: 30680 + 520 = 31200
Step 61: 31200 + 520 = 31720
Step 62: 31720 + 520 = 32240
Step 63: 32240 + 520 = 32760
Step 64: 32760 + 520 = 33280
Step 65: 33280 + 520 = 33800
Step 66: 33800 + 520 = 34320
Step 67: 34320 + 520 = 34840
Step 68: 34840 + 520 = 35360
Step 69: 35360 + 520 = 35880
Step 70: 35880 + 520 = 36400
Step 71: 36400 + 520 = 36920
Step 72: 36920 + 520 = 37440
Step 73: 37440 + 520 = 37960
Step 74: 37960 + 520 = 38480
Step 75: 38480 + 520 = 39000
Step 76: 39000 + 520 = 39520
Step 77: 39520 + 520 = 40040
Step 78: 40040 + 520 = 40560
Step 79: 40560 + 520 = 41080
Step 80: 41080 + 520 = 41600
Step 81: 41600 + 520 = 42120
Step 82: 42120 + 520 = 42640
Step 83: 42640 + 520 = 43160
Step 84: 43160 + 520 = 43680
Step 85: 43680 + 520 = 44200
Step 86: 44200 + 520 = 44720
Step 87: 44720 + 520 = 45240
Step 88: 45240 + 520 = 45760
Step 89: 45760 + 520 = 46280
Step 90: 46280 + 520 = 46800
Step 91: 46800 + 520 = 47320
Step 92: 47320 + 520 = 47840
Step 93: 47840 + 520 = 48360
Step 94: 48360 + 520 = 48880
Step 95: 48880 + 520 = 49400
Step 96: 49400 + 520 = 49920
Step 97: 49920 + 520 = 50440
Step 98: 50440 + 520 = 50960
Step 99: 50960 + 520 = 51480
Step 100: 51480 + 520 = 52000
Step 101: 52000 + 520 = 52520
Step 102: 52520 + 520 = 53040
Step 103: 53040 + 520 = 53560
Step 104: 53560 + 520 = 54080
Step 105: 54080 + 520 = 54600
Step 106: 54600 + 520 = 55120
Step 107: 55120 + 520 = 55640
Step 108: 55640 + 520 = 56160
Step 109: 56160 + 520 = 56680
Step 110: 56680 + 520 = 57200
Step 111: 57200 + 520 = 57720
Step 112: 57720 + 520 = 58240
Step 113: 58240 + 520 = 58760
Step 114: 58760 + 520 = 59280
Step 115: 59280 + 520 = 59800
Step 116: 59800 + 520 = 60320
Step 117: 60320 + 520 = 60840
Step 118: 60840 + 520 = 61360
Step 119: 61360 + 520 = 61880
Step 120: 61880 + 520 = 62400
Step 121: 62400 + 520 = 62920
Step 122: 62920 + 520 = 63440
Step 123: 63440 + 520 = 63960
Step 124: 63960 + 520 = 64480
Step 125: 64480 + 520 = 65000
Step 126: 65000 + 520 = 65520
Step 127: 65520 + 520 = 66040
Step 128: 66040 + 520 = 66560
Step 129: 66560 + 520 = 67080
Step 130: 67080 + 520 = 67600
Step 131: 67600 + 520 = 68120
Step 132: 68120 + 520 = 68640
Step 133: 68640 + 520 = 69160
Step 134: 69160 + 520 = 69680
Step 135: 69680 + 520 = 70200
Step 136: 70200 + 520 = 70720
Step 137: 70720 + 520 = 71240
Step 138: 71240 + 520 = 71760
Step 139: 71760 + 520 = 72280
Step 140: 72280 + 520 = 72800
Step 141: 72800 + 520 = 73320
Step 142: 73320 + 520 = 73840
Step 143: 73840 + 520 = 74360
Step 144: 74360 + 520 = 74880
Step 145: 74880 + 520 = 75400
Step 146: 75400 + 520 = 75920
Step 147: 75920 + 520 = 76440
Step 148: 76440 + 520 = 76960
Step 149: 76960 + 520 = 77480
Step 150: 77480 + 520 = 78000
Step 151: 78000 + 520 = 78520
Step 152: 78520 + 520 = 79040
Step 153: 79040 + 520 = 79560
Step 154: 79560 + 520 = 80080
Step 155: 80080 + 520 = 80600
Step 156: 80600 + 520 = 81120
Step 157: 81120 + 520 = 81640
Step 158: 81640 + 520 = 82160
Step 159: 82160 + 520 = 82680
Step 160: 82680 + 520 = 83200
Step 161: 83200 + 520 = 83720
Step 162: 83720 + 520 = 84240
Step 163: 84240 + 520 = 84760
Step 164: 84760 + 520 = 85280
Step 165: 85280 + 520 = 85800
Step 166: 85800 + 520 = 86320
Step 167: 86320 + 520 = 86840
Step 168: 86840 + 520 = 87360
Step 169: 87360 + 520 = 87880
Step 170: 87880 + 520 = 88400
Step 171: 88400 + 520 = 88920
Step 172: 88920 + 520 = 89440
Step 173: 89440 + 520 = 89960
Step 174: 89960 + 520 = 90480
Step 175: 90480 + 520 = 91000
Step 176: 91000 + 520 = 91520
Step 177: 91520 + 520 = 92040
Step 178: 92040 + 520 = 92560
Step 179: 92560 + 520 = 93080
Step 180: 93080 + 520 = 93600
Step 181: 93600 + 520 = 94120
Step 182: 94120 + 520 = 94640
Step 183: 94640 + 520 = 95160
Step 184: 95160 + 520 = 95680
Step 185: 95680 + 520 = 96200
Step 186: 96200 + 520 = 96720
Step 187: 96720 + 520 = 97240
Step 188: 97240 + 520 = 97760
Step 189: 97760 + 520 = 98280
Step 190: 98280 + 520 = 98800
Step 191: 98800 + 520 = 99320
Step 192: 99320 + 520 = 99840
Step 193: 99840 + 520 = 100360
Step 194: 100360 + 520 = 100880
Step 195: 100880 + 520 = 101400
Step 196: 101400 + 520 = 101920
Step 197: 101920 + 520 = 102440
Step 198: 102440 + 520 = 102960
Step 199: 102960 + 520 = 103480
Step 200: 103480 + 520 = 104000
Step 201: 104000 + 520 = 104520
Step 202: 104520 + 520 = 105040
Step 203: 105040 + 520 = 105560
Step 204: 105560 + 520 = 106080
Step 205: 106080 + 520 = 106600
Step 206: 106600 + 520 = 107120
Step 207: 107120 + 520 = 107640
Step 208: 107640 + 520 = 108160
Step 209: 108160 + 520 = 108680
Step 210: 108680 + 520 = 109200
Step 211: 109200 + 520 = 109720
Step 212: 109720 + 520 = 110240
Step 213: 110240 + 520 = 110760
Step 214: 110760 + 520 = 111280
Step 215: 111280 + 520 = 111800
Step 216: 111800 + 520 = 112320
Step 217: 112320 + 520 = 112840
Step 218: 112840 + 520 = 113360
Step 219: 113360 + 520 = 113880
Step 220: 113880 + 520 = 114400
Step 221: 114400 + 520 = 114920
Step 222: 114920 + 520 = 115440
Step 223: 115440 + 520 = 115960
Step 224: 115960 + 520 = 116480
Step 225: 116480 + 520 = 117000
Step 226: 117000 + 520 = 117520
Step 227: 117520 + 520 = 118040
Step 228: 118040 + 520 = 118560
Step 229: 118560 + 520 = 119080
Step 230: 119080 + 520 = 119600
Step 231: 119600 + 520 = 120120
Step 232: 120120 + 520 = 120640
Step 233: 120640 + 520 = 121160
Step 234: 121160 + 520 = 121680
Step 235: 121680 + 520 = 122200
Step 236: 122200 + 520 = 122720
Step 237: 122720 + 520 = 123240
Step 238: 123240 + 520 = 123760
Step 239: 123760 + 520 = 124280
Step 240: 124280 + 520 = 124800
Step 241: 124800 + 520 = 125320
Step 242: 125320 + 520 = 125840
Step 243: 125840 + 520 = 126360
Step 244: 126360 + 520 = 126880
Step 245: 126880 + 520 = 127400
Step 246: 127400 + 520 = 127920
Step 247: 127920 + 520 = 128440
Step 248: 128440 + 520 = 128960
Step 249: 128960 + 520 = 129480
Step 250: 129480 + 520 = 130000
Step 251: 130000 + 520 = 130520
Step 252: 130520 + 520 = 131040
Step 253: 131040 + 520 = 131560
Step 254: 131560 + 520 = 132080
Step 255: 132080 + 520 = 132600
Step 256: 132600 + 520 = 133120
Step 257: 133120 + 520 = 133640
Step 258: 133640 + 520 = 134160
Step 259: 134160 + 520 = 134680
Step 260: 134680 + 520 = 135200
Step 261: 135200 + 520 = 135720
Step 262: 135720 + 520 = 136240
Step 263: 136240 + 520 = 136760
Step 264: 136760 + 520 = 137280
Step 265: 137280 + 520 = 137800
Step 266: 137800 + 520 = 138320
Step 267: 138320 + 520 = 138840
Step 268: 138840 + 520 = 139360
Step 269: 139360 + 520 = 139880
Step 270: 139880 + 520 = 140400
Step 271: 140400 + 520 = 140920
Step 272: 140920 + 520 = 141440
Step 273: 141440 + 520 = 141960
Step 274: 141960 + 520 = 142480
Step 275: 142480 + 520 = 143000
Step 276: 143000 + 520 = 143520
Step 277: 143520 + 520 = 144040
Step 278: 144040 + 520 = 144560
Step 279: 144560 + 520 = 145080
Step 280: 145080 + 520 = 145600
Step 281: 145600 + 520 = 146120
Step 282: 146120 + 520 = 146640
Step 283: 146640 + 520 = 147160
Step 284: 147160 + 520 = 147680
Step 285: 147680 + 520 = 148200
Step 286: 148200 + 520 = 148720
Step 287: 148720 + 520 = 149240
Step 288: 149240 + 520 = 149760
Step 289: 149760 + 520 = 150280
Step 290: 150280 + 520 = 150800
Step 291: 150800 + 520 = 151320
Step 292: 151320 + 520 = 151840
Step 293: 151840 + 520 = 152360
Step 294: 152360 + 520 = 152880
Step 295: 152880 + 520 = 153400
Step 296: 153400 + 520 = 153920
Step 297: 153920 + 520 = 154440
Step 298: 154440 + 520 = 154960
Step 299: 154960 + 520 = 155480
Step 300: 155480 + 520 = 156000
Step 301: 156000 + 520 = 156520
Step 302: 156520 + 520 = 157040
Step 303: 157040 + 520 = 157560
Step 304: 157560 + 520 = 158080
Step 305: 158080 + 520 = 158600
Step 306: 158600 + 520 = 159120
Step 307: 159120 + 520 = 159640
Step 308: 159640 + 520 = 160160
Step 309: 160160 + 520 = 160680
Step 310: 160680 + 520 = 161200
Step 311: 161200 + 520 = 161720
Step 312: 161720 + 520 = 162240
Step 313: 162240 + 520 = 162760
Step 314: 162760 + 520 = 163280
Step 315: 163280 + 520 = 163800
Step 316: 163800 + 520 = 164320
Step 317: 164320 + 520 = 164840
Step 318: 164840 + 520 = 165360
Step 319: 165360 + 520 = 165880
Step 320: 165880 + 520 = 166400

So, 520*320 = 166400