8415 ÷ 8 = 1051 R7
Let's divide 8415 by 8.

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 (4) of the dividend behind the 0 and repeat the process: 4 / 8

Step 2:
8 goes into 4 0 times with a remainder of 4.
Write down 0 as next digit of of the result. 
Result so far: 10
Subtract 0 from 4 to get 4.
Bring next digit (1) of the dividend behind the 4 and repeat the process: 41 / 8

Step 3:
8 goes into 41 5 times with a remainder of 1.
Write down 5 as next digit of of the result. 
Result so far: 105
Subtract 40 from 41 to get 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 8

Step 4:
8 goes into 15 1 times with a remainder of 7.
Write down 1 as next digit of of the result. 
Result so far: 1051
Subtract 8 from 15 to get 7.

The final result is 1051 with a remainder of 7.