OK, let's work through this together. We're starting with 755 and we're going to multiply it by 86, which means we add 755 to itself 86 times.
Step 1: 0 + 755 = 755
Step 2: 755 + 755 = 1510
Step 3: 1510 + 755 = 2265
Step 4: 2265 + 755 = 3020
Step 5: 3020 + 755 = 3775
Step 6: 3775 + 755 = 4530
Step 7: 4530 + 755 = 5285
Step 8: 5285 + 755 = 6040
Step 9: 6040 + 755 = 6795
Step 10: 6795 + 755 = 7550
Step 11: 7550 + 755 = 8305
Step 12: 8305 + 755 = 9060
Step 13: 9060 + 755 = 9815
Step 14: 9815 + 755 = 10570
Step 15: 10570 + 755 = 11325
Step 16: 11325 + 755 = 12080
Step 17: 12080 + 755 = 12835
Step 18: 12835 + 755 = 13590
Step 19: 13590 + 755 = 14345
Step 20: 14345 + 755 = 15100
Step 21: 15100 + 755 = 15855
Step 22: 15855 + 755 = 16610
Step 23: 16610 + 755 = 17365
Step 24: 17365 + 755 = 18120
Step 25: 18120 + 755 = 18875
Step 26: 18875 + 755 = 19630
Step 27: 19630 + 755 = 20385
Step 28: 20385 + 755 = 21140
Step 29: 21140 + 755 = 21895
Step 30: 21895 + 755 = 22650
Step 31: 22650 + 755 = 23405
Step 32: 23405 + 755 = 24160
Step 33: 24160 + 755 = 24915
Step 34: 24915 + 755 = 25670
Step 35: 25670 + 755 = 26425
Step 36: 26425 + 755 = 27180
Step 37: 27180 + 755 = 27935
Step 38: 27935 + 755 = 28690
Step 39: 28690 + 755 = 29445
Step 40: 29445 + 755 = 30200
Step 41: 30200 + 755 = 30955
Step 42: 30955 + 755 = 31710
Step 43: 31710 + 755 = 32465
Step 44: 32465 + 755 = 33220
Step 45: 33220 + 755 = 33975
Step 46: 33975 + 755 = 34730
Step 47: 34730 + 755 = 35485
Step 48: 35485 + 755 = 36240
Step 49: 36240 + 755 = 36995
Step 50: 36995 + 755 = 37750
Step 51: 37750 + 755 = 38505
Step 52: 38505 + 755 = 39260
Step 53: 39260 + 755 = 40015
Step 54: 40015 + 755 = 40770
Step 55: 40770 + 755 = 41525
Step 56: 41525 + 755 = 42280
Step 57: 42280 + 755 = 43035
Step 58: 43035 + 755 = 43790
Step 59: 43790 + 755 = 44545
Step 60: 44545 + 755 = 45300
Step 61: 45300 + 755 = 46055
Step 62: 46055 + 755 = 46810
Step 63: 46810 + 755 = 47565
Step 64: 47565 + 755 = 48320
Step 65: 48320 + 755 = 49075
Step 66: 49075 + 755 = 49830
Step 67: 49830 + 755 = 50585
Step 68: 50585 + 755 = 51340
Step 69: 51340 + 755 = 52095
Step 70: 52095 + 755 = 52850
Step 71: 52850 + 755 = 53605
Step 72: 53605 + 755 = 54360
Step 73: 54360 + 755 = 55115
Step 74: 55115 + 755 = 55870
Step 75: 55870 + 755 = 56625
Step 76: 56625 + 755 = 57380
Step 77: 57380 + 755 = 58135
Step 78: 58135 + 755 = 58890
Step 79: 58890 + 755 = 59645
Step 80: 59645 + 755 = 60400
Step 81: 60400 + 755 = 61155
Step 82: 61155 + 755 = 61910
Step 83: 61910 + 755 = 62665
Step 84: 62665 + 755 = 63420
Step 85: 63420 + 755 = 64175
Step 86: 64175 + 755 = 64930

So, 755*86 = 64930