OK, let's work through this together. We're starting with 964 and we're going to multiply it by 86, which means we add 964 to itself 86 times.
Step 1: 0 + 964 = 964
Step 2: 964 + 964 = 1928
Step 3: 1928 + 964 = 2892
Step 4: 2892 + 964 = 3856
Step 5: 3856 + 964 = 4820
Step 6: 4820 + 964 = 5784
Step 7: 5784 + 964 = 6748
Step 8: 6748 + 964 = 7712
Step 9: 7712 + 964 = 8676
Step 10: 8676 + 964 = 9640
Step 11: 9640 + 964 = 10604
Step 12: 10604 + 964 = 11568
Step 13: 11568 + 964 = 12532
Step 14: 12532 + 964 = 13496
Step 15: 13496 + 964 = 14460
Step 16: 14460 + 964 = 15424
Step 17: 15424 + 964 = 16388
Step 18: 16388 + 964 = 17352
Step 19: 17352 + 964 = 18316
Step 20: 18316 + 964 = 19280
Step 21: 19280 + 964 = 20244
Step 22: 20244 + 964 = 21208
Step 23: 21208 + 964 = 22172
Step 24: 22172 + 964 = 23136
Step 25: 23136 + 964 = 24100
Step 26: 24100 + 964 = 25064
Step 27: 25064 + 964 = 26028
Step 28: 26028 + 964 = 26992
Step 29: 26992 + 964 = 27956
Step 30: 27956 + 964 = 28920
Step 31: 28920 + 964 = 29884
Step 32: 29884 + 964 = 30848
Step 33: 30848 + 964 = 31812
Step 34: 31812 + 964 = 32776
Step 35: 32776 + 964 = 33740
Step 36: 33740 + 964 = 34704
Step 37: 34704 + 964 = 35668
Step 38: 35668 + 964 = 36632
Step 39: 36632 + 964 = 37596
Step 40: 37596 + 964 = 38560
Step 41: 38560 + 964 = 39524
Step 42: 39524 + 964 = 40488
Step 43: 40488 + 964 = 41452
Step 44: 41452 + 964 = 42416
Step 45: 42416 + 964 = 43380
Step 46: 43380 + 964 = 44344
Step 47: 44344 + 964 = 45308
Step 48: 45308 + 964 = 46272
Step 49: 46272 + 964 = 47236
Step 50: 47236 + 964 = 48200
Step 51: 48200 + 964 = 49164
Step 52: 49164 + 964 = 50128
Step 53: 50128 + 964 = 51092
Step 54: 51092 + 964 = 52056
Step 55: 52056 + 964 = 53020
Step 56: 53020 + 964 = 53984
Step 57: 53984 + 964 = 54948
Step 58: 54948 + 964 = 55912
Step 59: 55912 + 964 = 56876
Step 60: 56876 + 964 = 57840
Step 61: 57840 + 964 = 58804
Step 62: 58804 + 964 = 59768
Step 63: 59768 + 964 = 60732
Step 64: 60732 + 964 = 61696
Step 65: 61696 + 964 = 62660
Step 66: 62660 + 964 = 63624
Step 67: 63624 + 964 = 64588
Step 68: 64588 + 964 = 65552
Step 69: 65552 + 964 = 66516
Step 70: 66516 + 964 = 67480
Step 71: 67480 + 964 = 68444
Step 72: 68444 + 964 = 69408
Step 73: 69408 + 964 = 70372
Step 74: 70372 + 964 = 71336
Step 75: 71336 + 964 = 72300
Step 76: 72300 + 964 = 73264
Step 77: 73264 + 964 = 74228
Step 78: 74228 + 964 = 75192
Step 79: 75192 + 964 = 76156
Step 80: 76156 + 964 = 77120
Step 81: 77120 + 964 = 78084
Step 82: 78084 + 964 = 79048
Step 83: 79048 + 964 = 80012
Step 84: 80012 + 964 = 80976
Step 85: 80976 + 964 = 81940
Step 86: 81940 + 964 = 82904

So, 964*86 = 82904