40407 ÷ 9 = 4489 R6
Let's divide 40407 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 (0) of the dividend behind the 4 and repeat the process: 40 / 9

Step 2:
9 goes into 40 4 times with a remainder of 4.
Write down 4 as next digit of of the result. 
Result so far: 4
Subtract 36 from 40 to get 4.
Bring next digit (4) of the dividend behind the 4 and repeat the process: 44 / 9

Step 3:
9 goes into 44 4 times with a remainder of 8.
Write down 4 as next digit of of the result. 
Result so far: 44
Subtract 36 from 44 to get 8.
Bring next digit (0) of the dividend behind the 8 and repeat the process: 80 / 9

Step 4:
9 goes into 80 8 times with a remainder of 8.
Write down 8 as next digit of of the result. 
Result so far: 448
Subtract 72 from 80 to get 8.
Bring next digit (7) of the dividend behind the 8 and repeat the process: 87 / 9

Step 5:
9 goes into 87 9 times with a remainder of 6.
Write down 9 as next digit of of the result. 
Result so far: 4489
Subtract 81 from 87 to get 6.

The final result is 4489 with a remainder of 6.