51551 ÷ 8 = 6443 R7
We're going to perform division on 51551 with 8 as the divisor.

Step 1:
8 goes into 5 0 times with a remainder of 5.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 5 to get 5.
Bring next digit (1) of the dividend behind the 5 and repeat the process: 51 / 8

Step 2:
8 goes into 51 6 times with a remainder of 3.
Write down 6 as next digit of of the result. 
Result so far: 6
Subtract 48 from 51 to get 3.
Bring next digit (5) of the dividend behind the 3 and repeat the process: 35 / 8

Step 3:
8 goes into 35 4 times with a remainder of 3.
Write down 4 as next digit of of the result. 
Result so far: 64
Subtract 32 from 35 to get 3.
Bring next digit (5) of the dividend behind the 3 and repeat the process: 35 / 8

Step 4:
8 goes into 35 4 times with a remainder of 3.
Write down 4 as next digit of of the result. 
Result so far: 644
Subtract 32 from 35 to get 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 8

Step 5:
8 goes into 31 3 times with a remainder of 7.
Write down 3 as next digit of of the result. 
Result so far: 6443
Subtract 24 from 31 to get 7.

The final result is 6443 with a remainder of 7.