86421 ÷ 8 = 10802 R5
Sure thing! Let's divide 86421 by 8 together.

Step 1:
8 goes into 8 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 8 from 8 to get 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 8

Step 2:
8 goes into 6 0 times with a remainder of 6.
Write down 0 as next digit of of the result. 
Result so far: 10
Subtract 0 from 6 to get 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 8

Step 3:
8 goes into 64 8 times with a remainder of 0.
Write down 8 as next digit of of the result. 
Result so far: 108
Subtract 64 from 64 to get 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 8

Step 4:
8 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of of the result. 
Result so far: 1080
Subtract 0 from 2 to get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 8

Step 5:
8 goes into 21 2 times with a remainder of 5.
Write down 2 as next digit of of the result. 
Result so far: 10802
Subtract 16 from 21 to get 5.

The final result is 10802 with a remainder of 5.