OK, let's work through this together. We're starting with 845 and we're going to multiply it by 103, which means we add 845 to itself 103 times.
Step 1: 0 + 845 = 845
Step 2: 845 + 845 = 1690
Step 3: 1690 + 845 = 2535
Step 4: 2535 + 845 = 3380
Step 5: 3380 + 845 = 4225
Step 6: 4225 + 845 = 5070
Step 7: 5070 + 845 = 5915
Step 8: 5915 + 845 = 6760
Step 9: 6760 + 845 = 7605
Step 10: 7605 + 845 = 8450
Step 11: 8450 + 845 = 9295
Step 12: 9295 + 845 = 10140
Step 13: 10140 + 845 = 10985
Step 14: 10985 + 845 = 11830
Step 15: 11830 + 845 = 12675
Step 16: 12675 + 845 = 13520
Step 17: 13520 + 845 = 14365
Step 18: 14365 + 845 = 15210
Step 19: 15210 + 845 = 16055
Step 20: 16055 + 845 = 16900
Step 21: 16900 + 845 = 17745
Step 22: 17745 + 845 = 18590
Step 23: 18590 + 845 = 19435
Step 24: 19435 + 845 = 20280
Step 25: 20280 + 845 = 21125
Step 26: 21125 + 845 = 21970
Step 27: 21970 + 845 = 22815
Step 28: 22815 + 845 = 23660
Step 29: 23660 + 845 = 24505
Step 30: 24505 + 845 = 25350
Step 31: 25350 + 845 = 26195
Step 32: 26195 + 845 = 27040
Step 33: 27040 + 845 = 27885
Step 34: 27885 + 845 = 28730
Step 35: 28730 + 845 = 29575
Step 36: 29575 + 845 = 30420
Step 37: 30420 + 845 = 31265
Step 38: 31265 + 845 = 32110
Step 39: 32110 + 845 = 32955
Step 40: 32955 + 845 = 33800
Step 41: 33800 + 845 = 34645
Step 42: 34645 + 845 = 35490
Step 43: 35490 + 845 = 36335
Step 44: 36335 + 845 = 37180
Step 45: 37180 + 845 = 38025
Step 46: 38025 + 845 = 38870
Step 47: 38870 + 845 = 39715
Step 48: 39715 + 845 = 40560
Step 49: 40560 + 845 = 41405
Step 50: 41405 + 845 = 42250
Step 51: 42250 + 845 = 43095
Step 52: 43095 + 845 = 43940
Step 53: 43940 + 845 = 44785
Step 54: 44785 + 845 = 45630
Step 55: 45630 + 845 = 46475
Step 56: 46475 + 845 = 47320
Step 57: 47320 + 845 = 48165
Step 58: 48165 + 845 = 49010
Step 59: 49010 + 845 = 49855
Step 60: 49855 + 845 = 50700
Step 61: 50700 + 845 = 51545
Step 62: 51545 + 845 = 52390
Step 63: 52390 + 845 = 53235
Step 64: 53235 + 845 = 54080
Step 65: 54080 + 845 = 54925
Step 66: 54925 + 845 = 55770
Step 67: 55770 + 845 = 56615
Step 68: 56615 + 845 = 57460
Step 69: 57460 + 845 = 58305
Step 70: 58305 + 845 = 59150
Step 71: 59150 + 845 = 59995
Step 72: 59995 + 845 = 60840
Step 73: 60840 + 845 = 61685
Step 74: 61685 + 845 = 62530
Step 75: 62530 + 845 = 63375
Step 76: 63375 + 845 = 64220
Step 77: 64220 + 845 = 65065
Step 78: 65065 + 845 = 65910
Step 79: 65910 + 845 = 66755
Step 80: 66755 + 845 = 67600
Step 81: 67600 + 845 = 68445
Step 82: 68445 + 845 = 69290
Step 83: 69290 + 845 = 70135
Step 84: 70135 + 845 = 70980
Step 85: 70980 + 845 = 71825
Step 86: 71825 + 845 = 72670
Step 87: 72670 + 845 = 73515
Step 88: 73515 + 845 = 74360
Step 89: 74360 + 845 = 75205
Step 90: 75205 + 845 = 76050
Step 91: 76050 + 845 = 76895
Step 92: 76895 + 845 = 77740
Step 93: 77740 + 845 = 78585
Step 94: 78585 + 845 = 79430
Step 95: 79430 + 845 = 80275
Step 96: 80275 + 845 = 81120
Step 97: 81120 + 845 = 81965
Step 98: 81965 + 845 = 82810
Step 99: 82810 + 845 = 83655
Step 100: 83655 + 845 = 84500
Step 101: 84500 + 845 = 85345
Step 102: 85345 + 845 = 86190
Step 103: 86190 + 845 = 87035

So, 845*103 = 87035