12423 ÷ 4 = 3105 R3
Let's divide 12423 by 4.

Step 1:
4 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 1 to get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 4

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

Step 3:
4 goes into 4 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 31
Subtract 4 from 4 to get 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 4

Step 4:
4 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of of the result. 
Result so far: 310
Subtract 0 from 2 to get 2.
Bring next digit (3) of the dividend behind the 2 and repeat the process: 23 / 4

Step 5:
4 goes into 23 5 times with a remainder of 3.
Write down 5 as next digit of of the result. 
Result so far: 3105
Subtract 20 from 23 to get 3.

The final result is 3105 with a remainder of 3.