OK, let's crack this. We're given 876 and our task is to multiply it by 85. Essentially, we'll be adding 876 to itself 85 times.
Step 1: 0 + 876 = 876
Step 2: 876 + 876 = 1752
Step 3: 1752 + 876 = 2628
Step 4: 2628 + 876 = 3504
Step 5: 3504 + 876 = 4380
Step 6: 4380 + 876 = 5256
Step 7: 5256 + 876 = 6132
Step 8: 6132 + 876 = 7008
Step 9: 7008 + 876 = 7884
Step 10: 7884 + 876 = 8760
Step 11: 8760 + 876 = 9636
Step 12: 9636 + 876 = 10512
Step 13: 10512 + 876 = 11388
Step 14: 11388 + 876 = 12264
Step 15: 12264 + 876 = 13140
Step 16: 13140 + 876 = 14016
Step 17: 14016 + 876 = 14892
Step 18: 14892 + 876 = 15768
Step 19: 15768 + 876 = 16644
Step 20: 16644 + 876 = 17520
Step 21: 17520 + 876 = 18396
Step 22: 18396 + 876 = 19272
Step 23: 19272 + 876 = 20148
Step 24: 20148 + 876 = 21024
Step 25: 21024 + 876 = 21900
Step 26: 21900 + 876 = 22776
Step 27: 22776 + 876 = 23652
Step 28: 23652 + 876 = 24528
Step 29: 24528 + 876 = 25404
Step 30: 25404 + 876 = 26280
Step 31: 26280 + 876 = 27156
Step 32: 27156 + 876 = 28032
Step 33: 28032 + 876 = 28908
Step 34: 28908 + 876 = 29784
Step 35: 29784 + 876 = 30660
Step 36: 30660 + 876 = 31536
Step 37: 31536 + 876 = 32412
Step 38: 32412 + 876 = 33288
Step 39: 33288 + 876 = 34164
Step 40: 34164 + 876 = 35040
Step 41: 35040 + 876 = 35916
Step 42: 35916 + 876 = 36792
Step 43: 36792 + 876 = 37668
Step 44: 37668 + 876 = 38544
Step 45: 38544 + 876 = 39420
Step 46: 39420 + 876 = 40296
Step 47: 40296 + 876 = 41172
Step 48: 41172 + 876 = 42048
Step 49: 42048 + 876 = 42924
Step 50: 42924 + 876 = 43800
Step 51: 43800 + 876 = 44676
Step 52: 44676 + 876 = 45552
Step 53: 45552 + 876 = 46428
Step 54: 46428 + 876 = 47304
Step 55: 47304 + 876 = 48180
Step 56: 48180 + 876 = 49056
Step 57: 49056 + 876 = 49932
Step 58: 49932 + 876 = 50808
Step 59: 50808 + 876 = 51684
Step 60: 51684 + 876 = 52560
Step 61: 52560 + 876 = 53436
Step 62: 53436 + 876 = 54312
Step 63: 54312 + 876 = 55188
Step 64: 55188 + 876 = 56064
Step 65: 56064 + 876 = 56940
Step 66: 56940 + 876 = 57816
Step 67: 57816 + 876 = 58692
Step 68: 58692 + 876 = 59568
Step 69: 59568 + 876 = 60444
Step 70: 60444 + 876 = 61320
Step 71: 61320 + 876 = 62196
Step 72: 62196 + 876 = 63072
Step 73: 63072 + 876 = 63948
Step 74: 63948 + 876 = 64824
Step 75: 64824 + 876 = 65700
Step 76: 65700 + 876 = 66576
Step 77: 66576 + 876 = 67452
Step 78: 67452 + 876 = 68328
Step 79: 68328 + 876 = 69204
Step 80: 69204 + 876 = 70080
Step 81: 70080 + 876 = 70956
Step 82: 70956 + 876 = 71832
Step 83: 71832 + 876 = 72708
Step 84: 72708 + 876 = 73584
Step 85: 73584 + 876 = 74460

So, 876*85 = 74460