Let's get this math done. We have 869 and we're going to multiply it by 87. This is the same as taking 869 and adding it to itself 87 times.
Step 1: 0 + 869 = 869
Step 2: 869 + 869 = 1738
Step 3: 1738 + 869 = 2607
Step 4: 2607 + 869 = 3476
Step 5: 3476 + 869 = 4345
Step 6: 4345 + 869 = 5214
Step 7: 5214 + 869 = 6083
Step 8: 6083 + 869 = 6952
Step 9: 6952 + 869 = 7821
Step 10: 7821 + 869 = 8690
Step 11: 8690 + 869 = 9559
Step 12: 9559 + 869 = 10428
Step 13: 10428 + 869 = 11297
Step 14: 11297 + 869 = 12166
Step 15: 12166 + 869 = 13035
Step 16: 13035 + 869 = 13904
Step 17: 13904 + 869 = 14773
Step 18: 14773 + 869 = 15642
Step 19: 15642 + 869 = 16511
Step 20: 16511 + 869 = 17380
Step 21: 17380 + 869 = 18249
Step 22: 18249 + 869 = 19118
Step 23: 19118 + 869 = 19987
Step 24: 19987 + 869 = 20856
Step 25: 20856 + 869 = 21725
Step 26: 21725 + 869 = 22594
Step 27: 22594 + 869 = 23463
Step 28: 23463 + 869 = 24332
Step 29: 24332 + 869 = 25201
Step 30: 25201 + 869 = 26070
Step 31: 26070 + 869 = 26939
Step 32: 26939 + 869 = 27808
Step 33: 27808 + 869 = 28677
Step 34: 28677 + 869 = 29546
Step 35: 29546 + 869 = 30415
Step 36: 30415 + 869 = 31284
Step 37: 31284 + 869 = 32153
Step 38: 32153 + 869 = 33022
Step 39: 33022 + 869 = 33891
Step 40: 33891 + 869 = 34760
Step 41: 34760 + 869 = 35629
Step 42: 35629 + 869 = 36498
Step 43: 36498 + 869 = 37367
Step 44: 37367 + 869 = 38236
Step 45: 38236 + 869 = 39105
Step 46: 39105 + 869 = 39974
Step 47: 39974 + 869 = 40843
Step 48: 40843 + 869 = 41712
Step 49: 41712 + 869 = 42581
Step 50: 42581 + 869 = 43450
Step 51: 43450 + 869 = 44319
Step 52: 44319 + 869 = 45188
Step 53: 45188 + 869 = 46057
Step 54: 46057 + 869 = 46926
Step 55: 46926 + 869 = 47795
Step 56: 47795 + 869 = 48664
Step 57: 48664 + 869 = 49533
Step 58: 49533 + 869 = 50402
Step 59: 50402 + 869 = 51271
Step 60: 51271 + 869 = 52140
Step 61: 52140 + 869 = 53009
Step 62: 53009 + 869 = 53878
Step 63: 53878 + 869 = 54747
Step 64: 54747 + 869 = 55616
Step 65: 55616 + 869 = 56485
Step 66: 56485 + 869 = 57354
Step 67: 57354 + 869 = 58223
Step 68: 58223 + 869 = 59092
Step 69: 59092 + 869 = 59961
Step 70: 59961 + 869 = 60830
Step 71: 60830 + 869 = 61699
Step 72: 61699 + 869 = 62568
Step 73: 62568 + 869 = 63437
Step 74: 63437 + 869 = 64306
Step 75: 64306 + 869 = 65175
Step 76: 65175 + 869 = 66044
Step 77: 66044 + 869 = 66913
Step 78: 66913 + 869 = 67782
Step 79: 67782 + 869 = 68651
Step 80: 68651 + 869 = 69520
Step 81: 69520 + 869 = 70389
Step 82: 70389 + 869 = 71258
Step 83: 71258 + 869 = 72127
Step 84: 72127 + 869 = 72996
Step 85: 72996 + 869 = 73865
Step 86: 73865 + 869 = 74734
Step 87: 74734 + 869 = 75603

So, 869*87 = 75603