Alright, let's solve this math problem step by step. First, we have the number 866. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 81. So, we're going to take the number 866 and add it to itself 81 times.
Step 1: 0 + 866 = 866
Step 2: 866 + 866 = 1732
Step 3: 1732 + 866 = 2598
Step 4: 2598 + 866 = 3464
Step 5: 3464 + 866 = 4330
Step 6: 4330 + 866 = 5196
Step 7: 5196 + 866 = 6062
Step 8: 6062 + 866 = 6928
Step 9: 6928 + 866 = 7794
Step 10: 7794 + 866 = 8660
Step 11: 8660 + 866 = 9526
Step 12: 9526 + 866 = 10392
Step 13: 10392 + 866 = 11258
Step 14: 11258 + 866 = 12124
Step 15: 12124 + 866 = 12990
Step 16: 12990 + 866 = 13856
Step 17: 13856 + 866 = 14722
Step 18: 14722 + 866 = 15588
Step 19: 15588 + 866 = 16454
Step 20: 16454 + 866 = 17320
Step 21: 17320 + 866 = 18186
Step 22: 18186 + 866 = 19052
Step 23: 19052 + 866 = 19918
Step 24: 19918 + 866 = 20784
Step 25: 20784 + 866 = 21650
Step 26: 21650 + 866 = 22516
Step 27: 22516 + 866 = 23382
Step 28: 23382 + 866 = 24248
Step 29: 24248 + 866 = 25114
Step 30: 25114 + 866 = 25980
Step 31: 25980 + 866 = 26846
Step 32: 26846 + 866 = 27712
Step 33: 27712 + 866 = 28578
Step 34: 28578 + 866 = 29444
Step 35: 29444 + 866 = 30310
Step 36: 30310 + 866 = 31176
Step 37: 31176 + 866 = 32042
Step 38: 32042 + 866 = 32908
Step 39: 32908 + 866 = 33774
Step 40: 33774 + 866 = 34640
Step 41: 34640 + 866 = 35506
Step 42: 35506 + 866 = 36372
Step 43: 36372 + 866 = 37238
Step 44: 37238 + 866 = 38104
Step 45: 38104 + 866 = 38970
Step 46: 38970 + 866 = 39836
Step 47: 39836 + 866 = 40702
Step 48: 40702 + 866 = 41568
Step 49: 41568 + 866 = 42434
Step 50: 42434 + 866 = 43300
Step 51: 43300 + 866 = 44166
Step 52: 44166 + 866 = 45032
Step 53: 45032 + 866 = 45898
Step 54: 45898 + 866 = 46764
Step 55: 46764 + 866 = 47630
Step 56: 47630 + 866 = 48496
Step 57: 48496 + 866 = 49362
Step 58: 49362 + 866 = 50228
Step 59: 50228 + 866 = 51094
Step 60: 51094 + 866 = 51960
Step 61: 51960 + 866 = 52826
Step 62: 52826 + 866 = 53692
Step 63: 53692 + 866 = 54558
Step 64: 54558 + 866 = 55424
Step 65: 55424 + 866 = 56290
Step 66: 56290 + 866 = 57156
Step 67: 57156 + 866 = 58022
Step 68: 58022 + 866 = 58888
Step 69: 58888 + 866 = 59754
Step 70: 59754 + 866 = 60620
Step 71: 60620 + 866 = 61486
Step 72: 61486 + 866 = 62352
Step 73: 62352 + 866 = 63218
Step 74: 63218 + 866 = 64084
Step 75: 64084 + 866 = 64950
Step 76: 64950 + 866 = 65816
Step 77: 65816 + 866 = 66682
Step 78: 66682 + 866 = 67548
Step 79: 67548 + 866 = 68414
Step 80: 68414 + 866 = 69280
Step 81: 69280 + 866 = 70146

So, 866*81 = 70146