42447 ÷ 3 = 14149 R0
Alright, let's work through the division of 42447 by 3 step by step.

Step 1:
3 goes into 4 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 3 from 4 to get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 3

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

Step 3:
3 goes into 4 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 141
Subtract 3 from 4 to get 1.
Bring next digit (4) of the dividend behind the 1 and repeat the process: 14 / 3

Step 4:
3 goes into 14 4 times with a remainder of 2.
Write down 4 as next digit of of the result. 
Result so far: 1414
Subtract 12 from 14 to get 2.
Bring next digit (7) of the dividend behind the 2 and repeat the process: 27 / 3

Step 5:
3 goes into 27 9 times with a remainder of 0.
Write down 9 as next digit of of the result. 
Result so far: 14149
Subtract 27 from 27 to get 0.

The final result is 14149 with a remainder of 0.