99678 ÷ 8 = 12459 R6
We're going to perform division on 99678 with 8 as the divisor.

Step 1:
8 goes into 9 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 8 from 9 to get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 8

Step 2:
8 goes into 19 2 times with a remainder of 3.
Write down 2 as next digit of of the result. 
Result so far: 12
Subtract 16 from 19 to get 3.
Bring next digit (6) of the dividend behind the 3 and repeat the process: 36 / 8

Step 3:
8 goes into 36 4 times with a remainder of 4.
Write down 4 as next digit of of the result. 
Result so far: 124
Subtract 32 from 36 to get 4.
Bring next digit (7) of the dividend behind the 4 and repeat the process: 47 / 8

Step 4:
8 goes into 47 5 times with a remainder of 7.
Write down 5 as next digit of of the result. 
Result so far: 1245
Subtract 40 from 47 to get 7.
Bring next digit (8) of the dividend behind the 7 and repeat the process: 78 / 8

Step 5:
8 goes into 78 9 times with a remainder of 6.
Write down 9 as next digit of of the result. 
Result so far: 12459
Subtract 72 from 78 to get 6.

The final result is 12459 with a remainder of 6.