31403 ÷ 3 = 10467 R2
We're going to perform division on 31403 with 3 as the divisor.

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

Step 2:
3 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 10
Subtract 0 from 1 to get 1.
Bring next digit (4) of the dividend behind the 1 and repeat the process: 14 / 3

Step 3:
3 goes into 14 4 times with a remainder of 2.
Write down 4 as next digit of of the result. 
Result so far: 104
Subtract 12 from 14 to get 2.
Bring next digit (0) of the dividend behind the 2 and repeat the process: 20 / 3

Step 4:
3 goes into 20 6 times with a remainder of 2.
Write down 6 as next digit of of the result. 
Result so far: 1046
Subtract 18 from 20 to get 2.
Bring next digit (3) of the dividend behind the 2 and repeat the process: 23 / 3

Step 5:
3 goes into 23 7 times with a remainder of 2.
Write down 7 as next digit of of the result. 
Result so far: 10467
Subtract 21 from 23 to get 2.

The final result is 10467 with a remainder of 2.