Let's roll up our sleeves and solve this. We have 857 and we're going to multiply it by 348, essentially adding 857 to itself 348 times.
Step 1: 0 + 857 = 857
Step 2: 857 + 857 = 1714
Step 3: 1714 + 857 = 2571
Step 4: 2571 + 857 = 3428
Step 5: 3428 + 857 = 4285
Step 6: 4285 + 857 = 5142
Step 7: 5142 + 857 = 5999
Step 8: 5999 + 857 = 6856
Step 9: 6856 + 857 = 7713
Step 10: 7713 + 857 = 8570
Step 11: 8570 + 857 = 9427
Step 12: 9427 + 857 = 10284
Step 13: 10284 + 857 = 11141
Step 14: 11141 + 857 = 11998
Step 15: 11998 + 857 = 12855
Step 16: 12855 + 857 = 13712
Step 17: 13712 + 857 = 14569
Step 18: 14569 + 857 = 15426
Step 19: 15426 + 857 = 16283
Step 20: 16283 + 857 = 17140
Step 21: 17140 + 857 = 17997
Step 22: 17997 + 857 = 18854
Step 23: 18854 + 857 = 19711
Step 24: 19711 + 857 = 20568
Step 25: 20568 + 857 = 21425
Step 26: 21425 + 857 = 22282
Step 27: 22282 + 857 = 23139
Step 28: 23139 + 857 = 23996
Step 29: 23996 + 857 = 24853
Step 30: 24853 + 857 = 25710
Step 31: 25710 + 857 = 26567
Step 32: 26567 + 857 = 27424
Step 33: 27424 + 857 = 28281
Step 34: 28281 + 857 = 29138
Step 35: 29138 + 857 = 29995
Step 36: 29995 + 857 = 30852
Step 37: 30852 + 857 = 31709
Step 38: 31709 + 857 = 32566
Step 39: 32566 + 857 = 33423
Step 40: 33423 + 857 = 34280
Step 41: 34280 + 857 = 35137
Step 42: 35137 + 857 = 35994
Step 43: 35994 + 857 = 36851
Step 44: 36851 + 857 = 37708
Step 45: 37708 + 857 = 38565
Step 46: 38565 + 857 = 39422
Step 47: 39422 + 857 = 40279
Step 48: 40279 + 857 = 41136
Step 49: 41136 + 857 = 41993
Step 50: 41993 + 857 = 42850
Step 51: 42850 + 857 = 43707
Step 52: 43707 + 857 = 44564
Step 53: 44564 + 857 = 45421
Step 54: 45421 + 857 = 46278
Step 55: 46278 + 857 = 47135
Step 56: 47135 + 857 = 47992
Step 57: 47992 + 857 = 48849
Step 58: 48849 + 857 = 49706
Step 59: 49706 + 857 = 50563
Step 60: 50563 + 857 = 51420
Step 61: 51420 + 857 = 52277
Step 62: 52277 + 857 = 53134
Step 63: 53134 + 857 = 53991
Step 64: 53991 + 857 = 54848
Step 65: 54848 + 857 = 55705
Step 66: 55705 + 857 = 56562
Step 67: 56562 + 857 = 57419
Step 68: 57419 + 857 = 58276
Step 69: 58276 + 857 = 59133
Step 70: 59133 + 857 = 59990
Step 71: 59990 + 857 = 60847
Step 72: 60847 + 857 = 61704
Step 73: 61704 + 857 = 62561
Step 74: 62561 + 857 = 63418
Step 75: 63418 + 857 = 64275
Step 76: 64275 + 857 = 65132
Step 77: 65132 + 857 = 65989
Step 78: 65989 + 857 = 66846
Step 79: 66846 + 857 = 67703
Step 80: 67703 + 857 = 68560
Step 81: 68560 + 857 = 69417
Step 82: 69417 + 857 = 70274
Step 83: 70274 + 857 = 71131
Step 84: 71131 + 857 = 71988
Step 85: 71988 + 857 = 72845
Step 86: 72845 + 857 = 73702
Step 87: 73702 + 857 = 74559
Step 88: 74559 + 857 = 75416
Step 89: 75416 + 857 = 76273
Step 90: 76273 + 857 = 77130
Step 91: 77130 + 857 = 77987
Step 92: 77987 + 857 = 78844
Step 93: 78844 + 857 = 79701
Step 94: 79701 + 857 = 80558
Step 95: 80558 + 857 = 81415
Step 96: 81415 + 857 = 82272
Step 97: 82272 + 857 = 83129
Step 98: 83129 + 857 = 83986
Step 99: 83986 + 857 = 84843
Step 100: 84843 + 857 = 85700
Step 101: 85700 + 857 = 86557
Step 102: 86557 + 857 = 87414
Step 103: 87414 + 857 = 88271
Step 104: 88271 + 857 = 89128
Step 105: 89128 + 857 = 89985
Step 106: 89985 + 857 = 90842
Step 107: 90842 + 857 = 91699
Step 108: 91699 + 857 = 92556
Step 109: 92556 + 857 = 93413
Step 110: 93413 + 857 = 94270
Step 111: 94270 + 857 = 95127
Step 112: 95127 + 857 = 95984
Step 113: 95984 + 857 = 96841
Step 114: 96841 + 857 = 97698
Step 115: 97698 + 857 = 98555
Step 116: 98555 + 857 = 99412
Step 117: 99412 + 857 = 100269
Step 118: 100269 + 857 = 101126
Step 119: 101126 + 857 = 101983
Step 120: 101983 + 857 = 102840
Step 121: 102840 + 857 = 103697
Step 122: 103697 + 857 = 104554
Step 123: 104554 + 857 = 105411
Step 124: 105411 + 857 = 106268
Step 125: 106268 + 857 = 107125
Step 126: 107125 + 857 = 107982
Step 127: 107982 + 857 = 108839
Step 128: 108839 + 857 = 109696
Step 129: 109696 + 857 = 110553
Step 130: 110553 + 857 = 111410
Step 131: 111410 + 857 = 112267
Step 132: 112267 + 857 = 113124
Step 133: 113124 + 857 = 113981
Step 134: 113981 + 857 = 114838
Step 135: 114838 + 857 = 115695
Step 136: 115695 + 857 = 116552
Step 137: 116552 + 857 = 117409
Step 138: 117409 + 857 = 118266
Step 139: 118266 + 857 = 119123
Step 140: 119123 + 857 = 119980
Step 141: 119980 + 857 = 120837
Step 142: 120837 + 857 = 121694
Step 143: 121694 + 857 = 122551
Step 144: 122551 + 857 = 123408
Step 145: 123408 + 857 = 124265
Step 146: 124265 + 857 = 125122
Step 147: 125122 + 857 = 125979
Step 148: 125979 + 857 = 126836
Step 149: 126836 + 857 = 127693
Step 150: 127693 + 857 = 128550
Step 151: 128550 + 857 = 129407
Step 152: 129407 + 857 = 130264
Step 153: 130264 + 857 = 131121
Step 154: 131121 + 857 = 131978
Step 155: 131978 + 857 = 132835
Step 156: 132835 + 857 = 133692
Step 157: 133692 + 857 = 134549
Step 158: 134549 + 857 = 135406
Step 159: 135406 + 857 = 136263
Step 160: 136263 + 857 = 137120
Step 161: 137120 + 857 = 137977
Step 162: 137977 + 857 = 138834
Step 163: 138834 + 857 = 139691
Step 164: 139691 + 857 = 140548
Step 165: 140548 + 857 = 141405
Step 166: 141405 + 857 = 142262
Step 167: 142262 + 857 = 143119
Step 168: 143119 + 857 = 143976
Step 169: 143976 + 857 = 144833
Step 170: 144833 + 857 = 145690
Step 171: 145690 + 857 = 146547
Step 172: 146547 + 857 = 147404
Step 173: 147404 + 857 = 148261
Step 174: 148261 + 857 = 149118
Step 175: 149118 + 857 = 149975
Step 176: 149975 + 857 = 150832
Step 177: 150832 + 857 = 151689
Step 178: 151689 + 857 = 152546
Step 179: 152546 + 857 = 153403
Step 180: 153403 + 857 = 154260
Step 181: 154260 + 857 = 155117
Step 182: 155117 + 857 = 155974
Step 183: 155974 + 857 = 156831
Step 184: 156831 + 857 = 157688
Step 185: 157688 + 857 = 158545
Step 186: 158545 + 857 = 159402
Step 187: 159402 + 857 = 160259
Step 188: 160259 + 857 = 161116
Step 189: 161116 + 857 = 161973
Step 190: 161973 + 857 = 162830
Step 191: 162830 + 857 = 163687
Step 192: 163687 + 857 = 164544
Step 193: 164544 + 857 = 165401
Step 194: 165401 + 857 = 166258
Step 195: 166258 + 857 = 167115
Step 196: 167115 + 857 = 167972
Step 197: 167972 + 857 = 168829
Step 198: 168829 + 857 = 169686
Step 199: 169686 + 857 = 170543
Step 200: 170543 + 857 = 171400
Step 201: 171400 + 857 = 172257
Step 202: 172257 + 857 = 173114
Step 203: 173114 + 857 = 173971
Step 204: 173971 + 857 = 174828
Step 205: 174828 + 857 = 175685
Step 206: 175685 + 857 = 176542
Step 207: 176542 + 857 = 177399
Step 208: 177399 + 857 = 178256
Step 209: 178256 + 857 = 179113
Step 210: 179113 + 857 = 179970
Step 211: 179970 + 857 = 180827
Step 212: 180827 + 857 = 181684
Step 213: 181684 + 857 = 182541
Step 214: 182541 + 857 = 183398
Step 215: 183398 + 857 = 184255
Step 216: 184255 + 857 = 185112
Step 217: 185112 + 857 = 185969
Step 218: 185969 + 857 = 186826
Step 219: 186826 + 857 = 187683
Step 220: 187683 + 857 = 188540
Step 221: 188540 + 857 = 189397
Step 222: 189397 + 857 = 190254
Step 223: 190254 + 857 = 191111
Step 224: 191111 + 857 = 191968
Step 225: 191968 + 857 = 192825
Step 226: 192825 + 857 = 193682
Step 227: 193682 + 857 = 194539
Step 228: 194539 + 857 = 195396
Step 229: 195396 + 857 = 196253
Step 230: 196253 + 857 = 197110
Step 231: 197110 + 857 = 197967
Step 232: 197967 + 857 = 198824
Step 233: 198824 + 857 = 199681
Step 234: 199681 + 857 = 200538
Step 235: 200538 + 857 = 201395
Step 236: 201395 + 857 = 202252
Step 237: 202252 + 857 = 203109
Step 238: 203109 + 857 = 203966
Step 239: 203966 + 857 = 204823
Step 240: 204823 + 857 = 205680
Step 241: 205680 + 857 = 206537
Step 242: 206537 + 857 = 207394
Step 243: 207394 + 857 = 208251
Step 244: 208251 + 857 = 209108
Step 245: 209108 + 857 = 209965
Step 246: 209965 + 857 = 210822
Step 247: 210822 + 857 = 211679
Step 248: 211679 + 857 = 212536
Step 249: 212536 + 857 = 213393
Step 250: 213393 + 857 = 214250
Step 251: 214250 + 857 = 215107
Step 252: 215107 + 857 = 215964
Step 253: 215964 + 857 = 216821
Step 254: 216821 + 857 = 217678
Step 255: 217678 + 857 = 218535
Step 256: 218535 + 857 = 219392
Step 257: 219392 + 857 = 220249
Step 258: 220249 + 857 = 221106
Step 259: 221106 + 857 = 221963
Step 260: 221963 + 857 = 222820
Step 261: 222820 + 857 = 223677
Step 262: 223677 + 857 = 224534
Step 263: 224534 + 857 = 225391
Step 264: 225391 + 857 = 226248
Step 265: 226248 + 857 = 227105
Step 266: 227105 + 857 = 227962
Step 267: 227962 + 857 = 228819
Step 268: 228819 + 857 = 229676
Step 269: 229676 + 857 = 230533
Step 270: 230533 + 857 = 231390
Step 271: 231390 + 857 = 232247
Step 272: 232247 + 857 = 233104
Step 273: 233104 + 857 = 233961
Step 274: 233961 + 857 = 234818
Step 275: 234818 + 857 = 235675
Step 276: 235675 + 857 = 236532
Step 277: 236532 + 857 = 237389
Step 278: 237389 + 857 = 238246
Step 279: 238246 + 857 = 239103
Step 280: 239103 + 857 = 239960
Step 281: 239960 + 857 = 240817
Step 282: 240817 + 857 = 241674
Step 283: 241674 + 857 = 242531
Step 284: 242531 + 857 = 243388
Step 285: 243388 + 857 = 244245
Step 286: 244245 + 857 = 245102
Step 287: 245102 + 857 = 245959
Step 288: 245959 + 857 = 246816
Step 289: 246816 + 857 = 247673
Step 290: 247673 + 857 = 248530
Step 291: 248530 + 857 = 249387
Step 292: 249387 + 857 = 250244
Step 293: 250244 + 857 = 251101
Step 294: 251101 + 857 = 251958
Step 295: 251958 + 857 = 252815
Step 296: 252815 + 857 = 253672
Step 297: 253672 + 857 = 254529
Step 298: 254529 + 857 = 255386
Step 299: 255386 + 857 = 256243
Step 300: 256243 + 857 = 257100
Step 301: 257100 + 857 = 257957
Step 302: 257957 + 857 = 258814
Step 303: 258814 + 857 = 259671
Step 304: 259671 + 857 = 260528
Step 305: 260528 + 857 = 261385
Step 306: 261385 + 857 = 262242
Step 307: 262242 + 857 = 263099
Step 308: 263099 + 857 = 263956
Step 309: 263956 + 857 = 264813
Step 310: 264813 + 857 = 265670
Step 311: 265670 + 857 = 266527
Step 312: 266527 + 857 = 267384
Step 313: 267384 + 857 = 268241
Step 314: 268241 + 857 = 269098
Step 315: 269098 + 857 = 269955
Step 316: 269955 + 857 = 270812
Step 317: 270812 + 857 = 271669
Step 318: 271669 + 857 = 272526
Step 319: 272526 + 857 = 273383
Step 320: 273383 + 857 = 274240
Step 321: 274240 + 857 = 275097
Step 322: 275097 + 857 = 275954
Step 323: 275954 + 857 = 276811
Step 324: 276811 + 857 = 277668
Step 325: 277668 + 857 = 278525
Step 326: 278525 + 857 = 279382
Step 327: 279382 + 857 = 280239
Step 328: 280239 + 857 = 281096
Step 329: 281096 + 857 = 281953
Step 330: 281953 + 857 = 282810
Step 331: 282810 + 857 = 283667
Step 332: 283667 + 857 = 284524
Step 333: 284524 + 857 = 285381
Step 334: 285381 + 857 = 286238
Step 335: 286238 + 857 = 287095
Step 336: 287095 + 857 = 287952
Step 337: 287952 + 857 = 288809
Step 338: 288809 + 857 = 289666
Step 339: 289666 + 857 = 290523
Step 340: 290523 + 857 = 291380
Step 341: 291380 + 857 = 292237
Step 342: 292237 + 857 = 293094
Step 343: 293094 + 857 = 293951
Step 344: 293951 + 857 = 294808
Step 345: 294808 + 857 = 295665
Step 346: 295665 + 857 = 296522
Step 347: 296522 + 857 = 297379
Step 348: 297379 + 857 = 298236

So, 857*348 = 298236