64403 ÷ 9 = 7155 R8
Alright, let's work through the division of 64403 by 9 step by step.

Step 1:
9 goes into 6 0 times with a remainder of 6.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 6 to get 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 9

Step 2:
9 goes into 64 7 times with a remainder of 1.
Write down 7 as next digit of of the result. 
Result so far: 7
Subtract 63 from 64 to get 1.
Bring next digit (4) of the dividend behind the 1 and repeat the process: 14 / 9

Step 3:
9 goes into 14 1 times with a remainder of 5.
Write down 1 as next digit of of the result. 
Result so far: 71
Subtract 9 from 14 to get 5.
Bring next digit (0) of the dividend behind the 5 and repeat the process: 50 / 9

Step 4:
9 goes into 50 5 times with a remainder of 5.
Write down 5 as next digit of of the result. 
Result so far: 715
Subtract 45 from 50 to get 5.
Bring next digit (3) of the dividend behind the 5 and repeat the process: 53 / 9

Step 5:
9 goes into 53 5 times with a remainder of 8.
Write down 5 as next digit of of the result. 
Result so far: 7155
Subtract 45 from 53 to get 8.

The final result is 7155 with a remainder of 8.