OK, let's work through this together. We're starting with 806 and we're going to multiply it by 84, which means we add 806 to itself 84 times.
Step 1: 0 + 806 = 806
Step 2: 806 + 806 = 1612
Step 3: 1612 + 806 = 2418
Step 4: 2418 + 806 = 3224
Step 5: 3224 + 806 = 4030
Step 6: 4030 + 806 = 4836
Step 7: 4836 + 806 = 5642
Step 8: 5642 + 806 = 6448
Step 9: 6448 + 806 = 7254
Step 10: 7254 + 806 = 8060
Step 11: 8060 + 806 = 8866
Step 12: 8866 + 806 = 9672
Step 13: 9672 + 806 = 10478
Step 14: 10478 + 806 = 11284
Step 15: 11284 + 806 = 12090
Step 16: 12090 + 806 = 12896
Step 17: 12896 + 806 = 13702
Step 18: 13702 + 806 = 14508
Step 19: 14508 + 806 = 15314
Step 20: 15314 + 806 = 16120
Step 21: 16120 + 806 = 16926
Step 22: 16926 + 806 = 17732
Step 23: 17732 + 806 = 18538
Step 24: 18538 + 806 = 19344
Step 25: 19344 + 806 = 20150
Step 26: 20150 + 806 = 20956
Step 27: 20956 + 806 = 21762
Step 28: 21762 + 806 = 22568
Step 29: 22568 + 806 = 23374
Step 30: 23374 + 806 = 24180
Step 31: 24180 + 806 = 24986
Step 32: 24986 + 806 = 25792
Step 33: 25792 + 806 = 26598
Step 34: 26598 + 806 = 27404
Step 35: 27404 + 806 = 28210
Step 36: 28210 + 806 = 29016
Step 37: 29016 + 806 = 29822
Step 38: 29822 + 806 = 30628
Step 39: 30628 + 806 = 31434
Step 40: 31434 + 806 = 32240
Step 41: 32240 + 806 = 33046
Step 42: 33046 + 806 = 33852
Step 43: 33852 + 806 = 34658
Step 44: 34658 + 806 = 35464
Step 45: 35464 + 806 = 36270
Step 46: 36270 + 806 = 37076
Step 47: 37076 + 806 = 37882
Step 48: 37882 + 806 = 38688
Step 49: 38688 + 806 = 39494
Step 50: 39494 + 806 = 40300
Step 51: 40300 + 806 = 41106
Step 52: 41106 + 806 = 41912
Step 53: 41912 + 806 = 42718
Step 54: 42718 + 806 = 43524
Step 55: 43524 + 806 = 44330
Step 56: 44330 + 806 = 45136
Step 57: 45136 + 806 = 45942
Step 58: 45942 + 806 = 46748
Step 59: 46748 + 806 = 47554
Step 60: 47554 + 806 = 48360
Step 61: 48360 + 806 = 49166
Step 62: 49166 + 806 = 49972
Step 63: 49972 + 806 = 50778
Step 64: 50778 + 806 = 51584
Step 65: 51584 + 806 = 52390
Step 66: 52390 + 806 = 53196
Step 67: 53196 + 806 = 54002
Step 68: 54002 + 806 = 54808
Step 69: 54808 + 806 = 55614
Step 70: 55614 + 806 = 56420
Step 71: 56420 + 806 = 57226
Step 72: 57226 + 806 = 58032
Step 73: 58032 + 806 = 58838
Step 74: 58838 + 806 = 59644
Step 75: 59644 + 806 = 60450
Step 76: 60450 + 806 = 61256
Step 77: 61256 + 806 = 62062
Step 78: 62062 + 806 = 62868
Step 79: 62868 + 806 = 63674
Step 80: 63674 + 806 = 64480
Step 81: 64480 + 806 = 65286
Step 82: 65286 + 806 = 66092
Step 83: 66092 + 806 = 66898
Step 84: 66898 + 806 = 67704

So, 806*84 = 67704