42870 ÷ 9 = 4763 R3
Let's divide 42870 by 9.

Step 1:
9 goes into 4 0 times with a remainder of 4.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 4 to get 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 9

Step 2:
9 goes into 42 4 times with a remainder of 6.
Write down 4 as next digit of of the result. 
Result so far: 4
Subtract 36 from 42 to get 6.
Bring next digit (8) of the dividend behind the 6 and repeat the process: 68 / 9

Step 3:
9 goes into 68 7 times with a remainder of 5.
Write down 7 as next digit of of the result. 
Result so far: 47
Subtract 63 from 68 to get 5.
Bring next digit (7) of the dividend behind the 5 and repeat the process: 57 / 9

Step 4:
9 goes into 57 6 times with a remainder of 3.
Write down 6 as next digit of of the result. 
Result so far: 476
Subtract 54 from 57 to get 3.
Bring next digit (0) of the dividend behind the 3 and repeat the process: 30 / 9

Step 5:
9 goes into 30 3 times with a remainder of 3.
Write down 3 as next digit of of the result. 
Result so far: 4763
Subtract 27 from 30 to get 3.

The final result is 4763 with a remainder of 3.