400009 ÷ 42 
Let's see how many times 42 fits into 400009.

On to step 1:
When dividing 4 by 42, we get 0 with a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Bring next digit (0) of the dividend behind the 4 and repeat the process: 40 / 42

Going ahead to step 2:
42 goes into 40 0 times with a remainder of 40.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 40, we get 40.
Grab the next digit (0) from the dividend, add it to 40, then carry on: 400 / 42

Going ahead to step 3:
The number 42 fits into 400 9 times, leaving a remainder of 22.
The number 9 becomes the next digit in our result. 
Result so far: 9.0
Subtract 378 from 400 to get 22.
Include the next digit (0) from the dividend after 22, then repeat: 220 / 42

On to step 4:
When dividing 220 by 42, we get 5 with a remainder of 10.
The next digit of our result is 5. 
Result so far: 95.0
If we subtract 210 from 220, we get 10.
Append the next digit (0) from the dividend to 10 and continue with: 100 / 42

Advancing to step 5:
If we divide 100 by 42, we get 2 and a remainder of 16.
Put 2 as the next digit of the answer. 
Result so far: 952.0
The remainder is 16 after subtracting 84 from 100.
Include the next digit (9) from the dividend after 16, then repeat: 169 / 42

Let's proceed to step 6:
The number 42 fits into 169 4 times, leaving a remainder of 1.
Use 4 as the next digit of our solution. 
Result so far: 9524.0
If we take 168 away from 169, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 7:
If we divide 10 by 42, we get 0 and a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 9524.0
Subtract 0 from 10 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 8:
100 divided by 42 is 2 with a remainder of 16.
Record the quotient 2 as the next digit in the result. 
Result so far: 9524.02
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 9:
160 divided by 42 is 3 with a remainder of 34.
Record the quotient 3 as the next digit in the result. 
Result so far: 9524.023
The remainder is 34 after subtracting 126 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Let's proceed to step 10:
If we divide 340 by 42, we get 8 and a remainder of 4.
Write down 8 as next digit of the result. 
Result so far: 9524.0238
Deduct 336 from 340 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 11:
If we divide 40 by 42, we get 0 and a remainder of 40.
Use 0 as the next digit of our solution. 
Result so far: 9524.0238
The remainder is 40 after subtracting 0 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 12:
42 goes into 400 9 times with a remainder of 22.
Record the quotient 9 as the next digit in the result. 
Result so far: 9524.023809
If we subtract 378 from 400, we get 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

On to step 13:
The number 42 fits into 220 5 times, leaving a remainder of 10.
The next digit of our result is 5. 
Result so far: 9524.0238095
If we take 210 away from 220, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 14:
42 goes into 100 2 times with a remainder of 16.
Put 2 as the next digit of the answer. 
Result so far: 9524.02380952
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

The final result is 9524.02380952 with a remainder of 1.6e-08.