57399 ÷ 9 = 6377 R6
Let's divide 57399 by 9.

Step 1:
9 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 (7) of the dividend behind the 5 and repeat the process: 57 / 9

Step 2:
9 goes into 57 6 times with a remainder of 3.
Write down 6 as next digit of of the result. 
Result so far: 6
Subtract 54 from 57 to get 3.
Bring next digit (3) of the dividend behind the 3 and repeat the process: 33 / 9

Step 3:
9 goes into 33 3 times with a remainder of 6.
Write down 3 as next digit of of the result. 
Result so far: 63
Subtract 27 from 33 to get 6.
Bring next digit (9) of the dividend behind the 6 and repeat the process: 69 / 9

Step 4:
9 goes into 69 7 times with a remainder of 6.
Write down 7 as next digit of of the result. 
Result so far: 637
Subtract 63 from 69 to get 6.
Bring next digit (9) of the dividend behind the 6 and repeat the process: 69 / 9

Step 5:
9 goes into 69 7 times with a remainder of 6.
Write down 7 as next digit of of the result. 
Result so far: 6377
Subtract 63 from 69 to get 6.

The final result is 6377 with a remainder of 6.