51859 ÷ 6 = 8643 R1
No problem, we've got 51859 and 6 for the division.

Step 1:
6 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 / 6

Step 2:
6 goes into 51 8 times with a remainder of 3.
Write down 8 as next digit of of the result. 
Result so far: 8
Subtract 48 from 51 to get 3.
Bring next digit (8) of the dividend behind the 3 and repeat the process: 38 / 6

Step 3:
6 goes into 38 6 times with a remainder of 2.
Write down 6 as next digit of of the result. 
Result so far: 86
Subtract 36 from 38 to get 2.
Bring next digit (5) of the dividend behind the 2 and repeat the process: 25 / 6

Step 4:
6 goes into 25 4 times with a remainder of 1.
Write down 4 as next digit of of the result. 
Result so far: 864
Subtract 24 from 25 to get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 6

Step 5:
6 goes into 19 3 times with a remainder of 1.
Write down 3 as next digit of of the result. 
Result so far: 8643
Subtract 18 from 19 to get 1.

The final result is 8643 with a remainder of 1.