OK, let's work through this together. We're starting with 836 and we're going to multiply it by 378, which means we add 836 to itself 378 times.
Step 1: 0 + 836 = 836
Step 2: 836 + 836 = 1672
Step 3: 1672 + 836 = 2508
Step 4: 2508 + 836 = 3344
Step 5: 3344 + 836 = 4180
Step 6: 4180 + 836 = 5016
Step 7: 5016 + 836 = 5852
Step 8: 5852 + 836 = 6688
Step 9: 6688 + 836 = 7524
Step 10: 7524 + 836 = 8360
Step 11: 8360 + 836 = 9196
Step 12: 9196 + 836 = 10032
Step 13: 10032 + 836 = 10868
Step 14: 10868 + 836 = 11704
Step 15: 11704 + 836 = 12540
Step 16: 12540 + 836 = 13376
Step 17: 13376 + 836 = 14212
Step 18: 14212 + 836 = 15048
Step 19: 15048 + 836 = 15884
Step 20: 15884 + 836 = 16720
Step 21: 16720 + 836 = 17556
Step 22: 17556 + 836 = 18392
Step 23: 18392 + 836 = 19228
Step 24: 19228 + 836 = 20064
Step 25: 20064 + 836 = 20900
Step 26: 20900 + 836 = 21736
Step 27: 21736 + 836 = 22572
Step 28: 22572 + 836 = 23408
Step 29: 23408 + 836 = 24244
Step 30: 24244 + 836 = 25080
Step 31: 25080 + 836 = 25916
Step 32: 25916 + 836 = 26752
Step 33: 26752 + 836 = 27588
Step 34: 27588 + 836 = 28424
Step 35: 28424 + 836 = 29260
Step 36: 29260 + 836 = 30096
Step 37: 30096 + 836 = 30932
Step 38: 30932 + 836 = 31768
Step 39: 31768 + 836 = 32604
Step 40: 32604 + 836 = 33440
Step 41: 33440 + 836 = 34276
Step 42: 34276 + 836 = 35112
Step 43: 35112 + 836 = 35948
Step 44: 35948 + 836 = 36784
Step 45: 36784 + 836 = 37620
Step 46: 37620 + 836 = 38456
Step 47: 38456 + 836 = 39292
Step 48: 39292 + 836 = 40128
Step 49: 40128 + 836 = 40964
Step 50: 40964 + 836 = 41800
Step 51: 41800 + 836 = 42636
Step 52: 42636 + 836 = 43472
Step 53: 43472 + 836 = 44308
Step 54: 44308 + 836 = 45144
Step 55: 45144 + 836 = 45980
Step 56: 45980 + 836 = 46816
Step 57: 46816 + 836 = 47652
Step 58: 47652 + 836 = 48488
Step 59: 48488 + 836 = 49324
Step 60: 49324 + 836 = 50160
Step 61: 50160 + 836 = 50996
Step 62: 50996 + 836 = 51832
Step 63: 51832 + 836 = 52668
Step 64: 52668 + 836 = 53504
Step 65: 53504 + 836 = 54340
Step 66: 54340 + 836 = 55176
Step 67: 55176 + 836 = 56012
Step 68: 56012 + 836 = 56848
Step 69: 56848 + 836 = 57684
Step 70: 57684 + 836 = 58520
Step 71: 58520 + 836 = 59356
Step 72: 59356 + 836 = 60192
Step 73: 60192 + 836 = 61028
Step 74: 61028 + 836 = 61864
Step 75: 61864 + 836 = 62700
Step 76: 62700 + 836 = 63536
Step 77: 63536 + 836 = 64372
Step 78: 64372 + 836 = 65208
Step 79: 65208 + 836 = 66044
Step 80: 66044 + 836 = 66880
Step 81: 66880 + 836 = 67716
Step 82: 67716 + 836 = 68552
Step 83: 68552 + 836 = 69388
Step 84: 69388 + 836 = 70224
Step 85: 70224 + 836 = 71060
Step 86: 71060 + 836 = 71896
Step 87: 71896 + 836 = 72732
Step 88: 72732 + 836 = 73568
Step 89: 73568 + 836 = 74404
Step 90: 74404 + 836 = 75240
Step 91: 75240 + 836 = 76076
Step 92: 76076 + 836 = 76912
Step 93: 76912 + 836 = 77748
Step 94: 77748 + 836 = 78584
Step 95: 78584 + 836 = 79420
Step 96: 79420 + 836 = 80256
Step 97: 80256 + 836 = 81092
Step 98: 81092 + 836 = 81928
Step 99: 81928 + 836 = 82764
Step 100: 82764 + 836 = 83600
Step 101: 83600 + 836 = 84436
Step 102: 84436 + 836 = 85272
Step 103: 85272 + 836 = 86108
Step 104: 86108 + 836 = 86944
Step 105: 86944 + 836 = 87780
Step 106: 87780 + 836 = 88616
Step 107: 88616 + 836 = 89452
Step 108: 89452 + 836 = 90288
Step 109: 90288 + 836 = 91124
Step 110: 91124 + 836 = 91960
Step 111: 91960 + 836 = 92796
Step 112: 92796 + 836 = 93632
Step 113: 93632 + 836 = 94468
Step 114: 94468 + 836 = 95304
Step 115: 95304 + 836 = 96140
Step 116: 96140 + 836 = 96976
Step 117: 96976 + 836 = 97812
Step 118: 97812 + 836 = 98648
Step 119: 98648 + 836 = 99484
Step 120: 99484 + 836 = 100320
Step 121: 100320 + 836 = 101156
Step 122: 101156 + 836 = 101992
Step 123: 101992 + 836 = 102828
Step 124: 102828 + 836 = 103664
Step 125: 103664 + 836 = 104500
Step 126: 104500 + 836 = 105336
Step 127: 105336 + 836 = 106172
Step 128: 106172 + 836 = 107008
Step 129: 107008 + 836 = 107844
Step 130: 107844 + 836 = 108680
Step 131: 108680 + 836 = 109516
Step 132: 109516 + 836 = 110352
Step 133: 110352 + 836 = 111188
Step 134: 111188 + 836 = 112024
Step 135: 112024 + 836 = 112860
Step 136: 112860 + 836 = 113696
Step 137: 113696 + 836 = 114532
Step 138: 114532 + 836 = 115368
Step 139: 115368 + 836 = 116204
Step 140: 116204 + 836 = 117040
Step 141: 117040 + 836 = 117876
Step 142: 117876 + 836 = 118712
Step 143: 118712 + 836 = 119548
Step 144: 119548 + 836 = 120384
Step 145: 120384 + 836 = 121220
Step 146: 121220 + 836 = 122056
Step 147: 122056 + 836 = 122892
Step 148: 122892 + 836 = 123728
Step 149: 123728 + 836 = 124564
Step 150: 124564 + 836 = 125400
Step 151: 125400 + 836 = 126236
Step 152: 126236 + 836 = 127072
Step 153: 127072 + 836 = 127908
Step 154: 127908 + 836 = 128744
Step 155: 128744 + 836 = 129580
Step 156: 129580 + 836 = 130416
Step 157: 130416 + 836 = 131252
Step 158: 131252 + 836 = 132088
Step 159: 132088 + 836 = 132924
Step 160: 132924 + 836 = 133760
Step 161: 133760 + 836 = 134596
Step 162: 134596 + 836 = 135432
Step 163: 135432 + 836 = 136268
Step 164: 136268 + 836 = 137104
Step 165: 137104 + 836 = 137940
Step 166: 137940 + 836 = 138776
Step 167: 138776 + 836 = 139612
Step 168: 139612 + 836 = 140448
Step 169: 140448 + 836 = 141284
Step 170: 141284 + 836 = 142120
Step 171: 142120 + 836 = 142956
Step 172: 142956 + 836 = 143792
Step 173: 143792 + 836 = 144628
Step 174: 144628 + 836 = 145464
Step 175: 145464 + 836 = 146300
Step 176: 146300 + 836 = 147136
Step 177: 147136 + 836 = 147972
Step 178: 147972 + 836 = 148808
Step 179: 148808 + 836 = 149644
Step 180: 149644 + 836 = 150480
Step 181: 150480 + 836 = 151316
Step 182: 151316 + 836 = 152152
Step 183: 152152 + 836 = 152988
Step 184: 152988 + 836 = 153824
Step 185: 153824 + 836 = 154660
Step 186: 154660 + 836 = 155496
Step 187: 155496 + 836 = 156332
Step 188: 156332 + 836 = 157168
Step 189: 157168 + 836 = 158004
Step 190: 158004 + 836 = 158840
Step 191: 158840 + 836 = 159676
Step 192: 159676 + 836 = 160512
Step 193: 160512 + 836 = 161348
Step 194: 161348 + 836 = 162184
Step 195: 162184 + 836 = 163020
Step 196: 163020 + 836 = 163856
Step 197: 163856 + 836 = 164692
Step 198: 164692 + 836 = 165528
Step 199: 165528 + 836 = 166364
Step 200: 166364 + 836 = 167200
Step 201: 167200 + 836 = 168036
Step 202: 168036 + 836 = 168872
Step 203: 168872 + 836 = 169708
Step 204: 169708 + 836 = 170544
Step 205: 170544 + 836 = 171380
Step 206: 171380 + 836 = 172216
Step 207: 172216 + 836 = 173052
Step 208: 173052 + 836 = 173888
Step 209: 173888 + 836 = 174724
Step 210: 174724 + 836 = 175560
Step 211: 175560 + 836 = 176396
Step 212: 176396 + 836 = 177232
Step 213: 177232 + 836 = 178068
Step 214: 178068 + 836 = 178904
Step 215: 178904 + 836 = 179740
Step 216: 179740 + 836 = 180576
Step 217: 180576 + 836 = 181412
Step 218: 181412 + 836 = 182248
Step 219: 182248 + 836 = 183084
Step 220: 183084 + 836 = 183920
Step 221: 183920 + 836 = 184756
Step 222: 184756 + 836 = 185592
Step 223: 185592 + 836 = 186428
Step 224: 186428 + 836 = 187264
Step 225: 187264 + 836 = 188100
Step 226: 188100 + 836 = 188936
Step 227: 188936 + 836 = 189772
Step 228: 189772 + 836 = 190608
Step 229: 190608 + 836 = 191444
Step 230: 191444 + 836 = 192280
Step 231: 192280 + 836 = 193116
Step 232: 193116 + 836 = 193952
Step 233: 193952 + 836 = 194788
Step 234: 194788 + 836 = 195624
Step 235: 195624 + 836 = 196460
Step 236: 196460 + 836 = 197296
Step 237: 197296 + 836 = 198132
Step 238: 198132 + 836 = 198968
Step 239: 198968 + 836 = 199804
Step 240: 199804 + 836 = 200640
Step 241: 200640 + 836 = 201476
Step 242: 201476 + 836 = 202312
Step 243: 202312 + 836 = 203148
Step 244: 203148 + 836 = 203984
Step 245: 203984 + 836 = 204820
Step 246: 204820 + 836 = 205656
Step 247: 205656 + 836 = 206492
Step 248: 206492 + 836 = 207328
Step 249: 207328 + 836 = 208164
Step 250: 208164 + 836 = 209000
Step 251: 209000 + 836 = 209836
Step 252: 209836 + 836 = 210672
Step 253: 210672 + 836 = 211508
Step 254: 211508 + 836 = 212344
Step 255: 212344 + 836 = 213180
Step 256: 213180 + 836 = 214016
Step 257: 214016 + 836 = 214852
Step 258: 214852 + 836 = 215688
Step 259: 215688 + 836 = 216524
Step 260: 216524 + 836 = 217360
Step 261: 217360 + 836 = 218196
Step 262: 218196 + 836 = 219032
Step 263: 219032 + 836 = 219868
Step 264: 219868 + 836 = 220704
Step 265: 220704 + 836 = 221540
Step 266: 221540 + 836 = 222376
Step 267: 222376 + 836 = 223212
Step 268: 223212 + 836 = 224048
Step 269: 224048 + 836 = 224884
Step 270: 224884 + 836 = 225720
Step 271: 225720 + 836 = 226556
Step 272: 226556 + 836 = 227392
Step 273: 227392 + 836 = 228228
Step 274: 228228 + 836 = 229064
Step 275: 229064 + 836 = 229900
Step 276: 229900 + 836 = 230736
Step 277: 230736 + 836 = 231572
Step 278: 231572 + 836 = 232408
Step 279: 232408 + 836 = 233244
Step 280: 233244 + 836 = 234080
Step 281: 234080 + 836 = 234916
Step 282: 234916 + 836 = 235752
Step 283: 235752 + 836 = 236588
Step 284: 236588 + 836 = 237424
Step 285: 237424 + 836 = 238260
Step 286: 238260 + 836 = 239096
Step 287: 239096 + 836 = 239932
Step 288: 239932 + 836 = 240768
Step 289: 240768 + 836 = 241604
Step 290: 241604 + 836 = 242440
Step 291: 242440 + 836 = 243276
Step 292: 243276 + 836 = 244112
Step 293: 244112 + 836 = 244948
Step 294: 244948 + 836 = 245784
Step 295: 245784 + 836 = 246620
Step 296: 246620 + 836 = 247456
Step 297: 247456 + 836 = 248292
Step 298: 248292 + 836 = 249128
Step 299: 249128 + 836 = 249964
Step 300: 249964 + 836 = 250800
Step 301: 250800 + 836 = 251636
Step 302: 251636 + 836 = 252472
Step 303: 252472 + 836 = 253308
Step 304: 253308 + 836 = 254144
Step 305: 254144 + 836 = 254980
Step 306: 254980 + 836 = 255816
Step 307: 255816 + 836 = 256652
Step 308: 256652 + 836 = 257488
Step 309: 257488 + 836 = 258324
Step 310: 258324 + 836 = 259160
Step 311: 259160 + 836 = 259996
Step 312: 259996 + 836 = 260832
Step 313: 260832 + 836 = 261668
Step 314: 261668 + 836 = 262504
Step 315: 262504 + 836 = 263340
Step 316: 263340 + 836 = 264176
Step 317: 264176 + 836 = 265012
Step 318: 265012 + 836 = 265848
Step 319: 265848 + 836 = 266684
Step 320: 266684 + 836 = 267520
Step 321: 267520 + 836 = 268356
Step 322: 268356 + 836 = 269192
Step 323: 269192 + 836 = 270028
Step 324: 270028 + 836 = 270864
Step 325: 270864 + 836 = 271700
Step 326: 271700 + 836 = 272536
Step 327: 272536 + 836 = 273372
Step 328: 273372 + 836 = 274208
Step 329: 274208 + 836 = 275044
Step 330: 275044 + 836 = 275880
Step 331: 275880 + 836 = 276716
Step 332: 276716 + 836 = 277552
Step 333: 277552 + 836 = 278388
Step 334: 278388 + 836 = 279224
Step 335: 279224 + 836 = 280060
Step 336: 280060 + 836 = 280896
Step 337: 280896 + 836 = 281732
Step 338: 281732 + 836 = 282568
Step 339: 282568 + 836 = 283404
Step 340: 283404 + 836 = 284240
Step 341: 284240 + 836 = 285076
Step 342: 285076 + 836 = 285912
Step 343: 285912 + 836 = 286748
Step 344: 286748 + 836 = 287584
Step 345: 287584 + 836 = 288420
Step 346: 288420 + 836 = 289256
Step 347: 289256 + 836 = 290092
Step 348: 290092 + 836 = 290928
Step 349: 290928 + 836 = 291764
Step 350: 291764 + 836 = 292600
Step 351: 292600 + 836 = 293436
Step 352: 293436 + 836 = 294272
Step 353: 294272 + 836 = 295108
Step 354: 295108 + 836 = 295944
Step 355: 295944 + 836 = 296780
Step 356: 296780 + 836 = 297616
Step 357: 297616 + 836 = 298452
Step 358: 298452 + 836 = 299288
Step 359: 299288 + 836 = 300124
Step 360: 300124 + 836 = 300960
Step 361: 300960 + 836 = 301796
Step 362: 301796 + 836 = 302632
Step 363: 302632 + 836 = 303468
Step 364: 303468 + 836 = 304304
Step 365: 304304 + 836 = 305140
Step 366: 305140 + 836 = 305976
Step 367: 305976 + 836 = 306812
Step 368: 306812 + 836 = 307648
Step 369: 307648 + 836 = 308484
Step 370: 308484 + 836 = 309320
Step 371: 309320 + 836 = 310156
Step 372: 310156 + 836 = 310992
Step 373: 310992 + 836 = 311828
Step 374: 311828 + 836 = 312664
Step 375: 312664 + 836 = 313500
Step 376: 313500 + 836 = 314336
Step 377: 314336 + 836 = 315172
Step 378: 315172 + 836 = 316008

So, 836*378 = 316008