OK, let's work through this together. We're starting with 78 and we're going to multiply it by 348, which means we add 78 to itself 348 times.
Step 1: 0 + 78 = 78
Step 2: 78 + 78 = 156
Step 3: 156 + 78 = 234
Step 4: 234 + 78 = 312
Step 5: 312 + 78 = 390
Step 6: 390 + 78 = 468
Step 7: 468 + 78 = 546
Step 8: 546 + 78 = 624
Step 9: 624 + 78 = 702
Step 10: 702 + 78 = 780
Step 11: 780 + 78 = 858
Step 12: 858 + 78 = 936
Step 13: 936 + 78 = 1014
Step 14: 1014 + 78 = 1092
Step 15: 1092 + 78 = 1170
Step 16: 1170 + 78 = 1248
Step 17: 1248 + 78 = 1326
Step 18: 1326 + 78 = 1404
Step 19: 1404 + 78 = 1482
Step 20: 1482 + 78 = 1560
Step 21: 1560 + 78 = 1638
Step 22: 1638 + 78 = 1716
Step 23: 1716 + 78 = 1794
Step 24: 1794 + 78 = 1872
Step 25: 1872 + 78 = 1950
Step 26: 1950 + 78 = 2028
Step 27: 2028 + 78 = 2106
Step 28: 2106 + 78 = 2184
Step 29: 2184 + 78 = 2262
Step 30: 2262 + 78 = 2340
Step 31: 2340 + 78 = 2418
Step 32: 2418 + 78 = 2496
Step 33: 2496 + 78 = 2574
Step 34: 2574 + 78 = 2652
Step 35: 2652 + 78 = 2730
Step 36: 2730 + 78 = 2808
Step 37: 2808 + 78 = 2886
Step 38: 2886 + 78 = 2964
Step 39: 2964 + 78 = 3042
Step 40: 3042 + 78 = 3120
Step 41: 3120 + 78 = 3198
Step 42: 3198 + 78 = 3276
Step 43: 3276 + 78 = 3354
Step 44: 3354 + 78 = 3432
Step 45: 3432 + 78 = 3510
Step 46: 3510 + 78 = 3588
Step 47: 3588 + 78 = 3666
Step 48: 3666 + 78 = 3744
Step 49: 3744 + 78 = 3822
Step 50: 3822 + 78 = 3900
Step 51: 3900 + 78 = 3978
Step 52: 3978 + 78 = 4056
Step 53: 4056 + 78 = 4134
Step 54: 4134 + 78 = 4212
Step 55: 4212 + 78 = 4290
Step 56: 4290 + 78 = 4368
Step 57: 4368 + 78 = 4446
Step 58: 4446 + 78 = 4524
Step 59: 4524 + 78 = 4602
Step 60: 4602 + 78 = 4680
Step 61: 4680 + 78 = 4758
Step 62: 4758 + 78 = 4836
Step 63: 4836 + 78 = 4914
Step 64: 4914 + 78 = 4992
Step 65: 4992 + 78 = 5070
Step 66: 5070 + 78 = 5148
Step 67: 5148 + 78 = 5226
Step 68: 5226 + 78 = 5304
Step 69: 5304 + 78 = 5382
Step 70: 5382 + 78 = 5460
Step 71: 5460 + 78 = 5538
Step 72: 5538 + 78 = 5616
Step 73: 5616 + 78 = 5694
Step 74: 5694 + 78 = 5772
Step 75: 5772 + 78 = 5850
Step 76: 5850 + 78 = 5928
Step 77: 5928 + 78 = 6006
Step 78: 6006 + 78 = 6084
Step 79: 6084 + 78 = 6162
Step 80: 6162 + 78 = 6240
Step 81: 6240 + 78 = 6318
Step 82: 6318 + 78 = 6396
Step 83: 6396 + 78 = 6474
Step 84: 6474 + 78 = 6552
Step 85: 6552 + 78 = 6630
Step 86: 6630 + 78 = 6708
Step 87: 6708 + 78 = 6786
Step 88: 6786 + 78 = 6864
Step 89: 6864 + 78 = 6942
Step 90: 6942 + 78 = 7020
Step 91: 7020 + 78 = 7098
Step 92: 7098 + 78 = 7176
Step 93: 7176 + 78 = 7254
Step 94: 7254 + 78 = 7332
Step 95: 7332 + 78 = 7410
Step 96: 7410 + 78 = 7488
Step 97: 7488 + 78 = 7566
Step 98: 7566 + 78 = 7644
Step 99: 7644 + 78 = 7722
Step 100: 7722 + 78 = 7800
Step 101: 7800 + 78 = 7878
Step 102: 7878 + 78 = 7956
Step 103: 7956 + 78 = 8034
Step 104: 8034 + 78 = 8112
Step 105: 8112 + 78 = 8190
Step 106: 8190 + 78 = 8268
Step 107: 8268 + 78 = 8346
Step 108: 8346 + 78 = 8424
Step 109: 8424 + 78 = 8502
Step 110: 8502 + 78 = 8580
Step 111: 8580 + 78 = 8658
Step 112: 8658 + 78 = 8736
Step 113: 8736 + 78 = 8814
Step 114: 8814 + 78 = 8892
Step 115: 8892 + 78 = 8970
Step 116: 8970 + 78 = 9048
Step 117: 9048 + 78 = 9126
Step 118: 9126 + 78 = 9204
Step 119: 9204 + 78 = 9282
Step 120: 9282 + 78 = 9360
Step 121: 9360 + 78 = 9438
Step 122: 9438 + 78 = 9516
Step 123: 9516 + 78 = 9594
Step 124: 9594 + 78 = 9672
Step 125: 9672 + 78 = 9750
Step 126: 9750 + 78 = 9828
Step 127: 9828 + 78 = 9906
Step 128: 9906 + 78 = 9984
Step 129: 9984 + 78 = 10062
Step 130: 10062 + 78 = 10140
Step 131: 10140 + 78 = 10218
Step 132: 10218 + 78 = 10296
Step 133: 10296 + 78 = 10374
Step 134: 10374 + 78 = 10452
Step 135: 10452 + 78 = 10530
Step 136: 10530 + 78 = 10608
Step 137: 10608 + 78 = 10686
Step 138: 10686 + 78 = 10764
Step 139: 10764 + 78 = 10842
Step 140: 10842 + 78 = 10920
Step 141: 10920 + 78 = 10998
Step 142: 10998 + 78 = 11076
Step 143: 11076 + 78 = 11154
Step 144: 11154 + 78 = 11232
Step 145: 11232 + 78 = 11310
Step 146: 11310 + 78 = 11388
Step 147: 11388 + 78 = 11466
Step 148: 11466 + 78 = 11544
Step 149: 11544 + 78 = 11622
Step 150: 11622 + 78 = 11700
Step 151: 11700 + 78 = 11778
Step 152: 11778 + 78 = 11856
Step 153: 11856 + 78 = 11934
Step 154: 11934 + 78 = 12012
Step 155: 12012 + 78 = 12090
Step 156: 12090 + 78 = 12168
Step 157: 12168 + 78 = 12246
Step 158: 12246 + 78 = 12324
Step 159: 12324 + 78 = 12402
Step 160: 12402 + 78 = 12480
Step 161: 12480 + 78 = 12558
Step 162: 12558 + 78 = 12636
Step 163: 12636 + 78 = 12714
Step 164: 12714 + 78 = 12792
Step 165: 12792 + 78 = 12870
Step 166: 12870 + 78 = 12948
Step 167: 12948 + 78 = 13026
Step 168: 13026 + 78 = 13104
Step 169: 13104 + 78 = 13182
Step 170: 13182 + 78 = 13260
Step 171: 13260 + 78 = 13338
Step 172: 13338 + 78 = 13416
Step 173: 13416 + 78 = 13494
Step 174: 13494 + 78 = 13572
Step 175: 13572 + 78 = 13650
Step 176: 13650 + 78 = 13728
Step 177: 13728 + 78 = 13806
Step 178: 13806 + 78 = 13884
Step 179: 13884 + 78 = 13962
Step 180: 13962 + 78 = 14040
Step 181: 14040 + 78 = 14118
Step 182: 14118 + 78 = 14196
Step 183: 14196 + 78 = 14274
Step 184: 14274 + 78 = 14352
Step 185: 14352 + 78 = 14430
Step 186: 14430 + 78 = 14508
Step 187: 14508 + 78 = 14586
Step 188: 14586 + 78 = 14664
Step 189: 14664 + 78 = 14742
Step 190: 14742 + 78 = 14820
Step 191: 14820 + 78 = 14898
Step 192: 14898 + 78 = 14976
Step 193: 14976 + 78 = 15054
Step 194: 15054 + 78 = 15132
Step 195: 15132 + 78 = 15210
Step 196: 15210 + 78 = 15288
Step 197: 15288 + 78 = 15366
Step 198: 15366 + 78 = 15444
Step 199: 15444 + 78 = 15522
Step 200: 15522 + 78 = 15600
Step 201: 15600 + 78 = 15678
Step 202: 15678 + 78 = 15756
Step 203: 15756 + 78 = 15834
Step 204: 15834 + 78 = 15912
Step 205: 15912 + 78 = 15990
Step 206: 15990 + 78 = 16068
Step 207: 16068 + 78 = 16146
Step 208: 16146 + 78 = 16224
Step 209: 16224 + 78 = 16302
Step 210: 16302 + 78 = 16380
Step 211: 16380 + 78 = 16458
Step 212: 16458 + 78 = 16536
Step 213: 16536 + 78 = 16614
Step 214: 16614 + 78 = 16692
Step 215: 16692 + 78 = 16770
Step 216: 16770 + 78 = 16848
Step 217: 16848 + 78 = 16926
Step 218: 16926 + 78 = 17004
Step 219: 17004 + 78 = 17082
Step 220: 17082 + 78 = 17160
Step 221: 17160 + 78 = 17238
Step 222: 17238 + 78 = 17316
Step 223: 17316 + 78 = 17394
Step 224: 17394 + 78 = 17472
Step 225: 17472 + 78 = 17550
Step 226: 17550 + 78 = 17628
Step 227: 17628 + 78 = 17706
Step 228: 17706 + 78 = 17784
Step 229: 17784 + 78 = 17862
Step 230: 17862 + 78 = 17940
Step 231: 17940 + 78 = 18018
Step 232: 18018 + 78 = 18096
Step 233: 18096 + 78 = 18174
Step 234: 18174 + 78 = 18252
Step 235: 18252 + 78 = 18330
Step 236: 18330 + 78 = 18408
Step 237: 18408 + 78 = 18486
Step 238: 18486 + 78 = 18564
Step 239: 18564 + 78 = 18642
Step 240: 18642 + 78 = 18720
Step 241: 18720 + 78 = 18798
Step 242: 18798 + 78 = 18876
Step 243: 18876 + 78 = 18954
Step 244: 18954 + 78 = 19032
Step 245: 19032 + 78 = 19110
Step 246: 19110 + 78 = 19188
Step 247: 19188 + 78 = 19266
Step 248: 19266 + 78 = 19344
Step 249: 19344 + 78 = 19422
Step 250: 19422 + 78 = 19500
Step 251: 19500 + 78 = 19578
Step 252: 19578 + 78 = 19656
Step 253: 19656 + 78 = 19734
Step 254: 19734 + 78 = 19812
Step 255: 19812 + 78 = 19890
Step 256: 19890 + 78 = 19968
Step 257: 19968 + 78 = 20046
Step 258: 20046 + 78 = 20124
Step 259: 20124 + 78 = 20202
Step 260: 20202 + 78 = 20280
Step 261: 20280 + 78 = 20358
Step 262: 20358 + 78 = 20436
Step 263: 20436 + 78 = 20514
Step 264: 20514 + 78 = 20592
Step 265: 20592 + 78 = 20670
Step 266: 20670 + 78 = 20748
Step 267: 20748 + 78 = 20826
Step 268: 20826 + 78 = 20904
Step 269: 20904 + 78 = 20982
Step 270: 20982 + 78 = 21060
Step 271: 21060 + 78 = 21138
Step 272: 21138 + 78 = 21216
Step 273: 21216 + 78 = 21294
Step 274: 21294 + 78 = 21372
Step 275: 21372 + 78 = 21450
Step 276: 21450 + 78 = 21528
Step 277: 21528 + 78 = 21606
Step 278: 21606 + 78 = 21684
Step 279: 21684 + 78 = 21762
Step 280: 21762 + 78 = 21840
Step 281: 21840 + 78 = 21918
Step 282: 21918 + 78 = 21996
Step 283: 21996 + 78 = 22074
Step 284: 22074 + 78 = 22152
Step 285: 22152 + 78 = 22230
Step 286: 22230 + 78 = 22308
Step 287: 22308 + 78 = 22386
Step 288: 22386 + 78 = 22464
Step 289: 22464 + 78 = 22542
Step 290: 22542 + 78 = 22620
Step 291: 22620 + 78 = 22698
Step 292: 22698 + 78 = 22776
Step 293: 22776 + 78 = 22854
Step 294: 22854 + 78 = 22932
Step 295: 22932 + 78 = 23010
Step 296: 23010 + 78 = 23088
Step 297: 23088 + 78 = 23166
Step 298: 23166 + 78 = 23244
Step 299: 23244 + 78 = 23322
Step 300: 23322 + 78 = 23400
Step 301: 23400 + 78 = 23478
Step 302: 23478 + 78 = 23556
Step 303: 23556 + 78 = 23634
Step 304: 23634 + 78 = 23712
Step 305: 23712 + 78 = 23790
Step 306: 23790 + 78 = 23868
Step 307: 23868 + 78 = 23946
Step 308: 23946 + 78 = 24024
Step 309: 24024 + 78 = 24102
Step 310: 24102 + 78 = 24180
Step 311: 24180 + 78 = 24258
Step 312: 24258 + 78 = 24336
Step 313: 24336 + 78 = 24414
Step 314: 24414 + 78 = 24492
Step 315: 24492 + 78 = 24570
Step 316: 24570 + 78 = 24648
Step 317: 24648 + 78 = 24726
Step 318: 24726 + 78 = 24804
Step 319: 24804 + 78 = 24882
Step 320: 24882 + 78 = 24960
Step 321: 24960 + 78 = 25038
Step 322: 25038 + 78 = 25116
Step 323: 25116 + 78 = 25194
Step 324: 25194 + 78 = 25272
Step 325: 25272 + 78 = 25350
Step 326: 25350 + 78 = 25428
Step 327: 25428 + 78 = 25506
Step 328: 25506 + 78 = 25584
Step 329: 25584 + 78 = 25662
Step 330: 25662 + 78 = 25740
Step 331: 25740 + 78 = 25818
Step 332: 25818 + 78 = 25896
Step 333: 25896 + 78 = 25974
Step 334: 25974 + 78 = 26052
Step 335: 26052 + 78 = 26130
Step 336: 26130 + 78 = 26208
Step 337: 26208 + 78 = 26286
Step 338: 26286 + 78 = 26364
Step 339: 26364 + 78 = 26442
Step 340: 26442 + 78 = 26520
Step 341: 26520 + 78 = 26598
Step 342: 26598 + 78 = 26676
Step 343: 26676 + 78 = 26754
Step 344: 26754 + 78 = 26832
Step 345: 26832 + 78 = 26910
Step 346: 26910 + 78 = 26988
Step 347: 26988 + 78 = 27066
Step 348: 27066 + 78 = 27144

So, 78*348 = 27144