421340 ÷ 24 
We want to figure out the number of times 421340 can be divided by 24.

Going ahead to step 1:
If we divide 4 by 24, we get 0 and a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Append the next digit (2) from the dividend to 4 and continue with: 42 / 24

On to step 2:
The number 24 fits into 42 1 times, leaving a remainder of 18.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtracting 24 from 42 leaves us with 18.
Bring next digit (1) of the dividend behind the 18 and repeat the process: 181 / 24

Moving on to step 3:
24 can be fit into 181 7 times, resulting in a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 17.0
If we subtract 168 from 181, we get 13.
Append the next digit (3) from the dividend to 13 and continue with: 133 / 24

Going ahead to step 4:
133 divided by 24 is 5 with a remainder of 13.
Write down 5 as next digit of the result. 
Result so far: 175.0
Subtract 120 from 133 to get 13.
Include the next digit (4) from the dividend after 13, then repeat: 134 / 24

Moving on to step 5:
When dividing 134 by 24, we get 5 with a remainder of 14.
The number 5 becomes the next digit in our result. 
Result so far: 1755.0
The remainder is 14 after subtracting 120 from 134.
Fetch the next digit (0) from the dividend, attach it to 14 and continue: 140 / 24

Step 6:
140 divided by 24 is 5 with a remainder of 20.
Use 5 as the next digit of our solution. 
Result so far: 17555.0
Deduct 120 from 140 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 7:
24 goes into 200 8 times with a remainder of 8.
The next digit of our result is 8. 
Result so far: 17555.8
The remainder is 8 after subtracting 192 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 8:
80 divided by 24 is 3 with a remainder of 8.
The number 3 becomes the next digit in our result. 
Result so far: 17555.83
Subtracting 72 from 80 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 9:
The number 24 fits into 80 3 times, leaving a remainder of 8.
Put 3 as the next digit of the answer. 
Result so far: 17555.833
Subtracting 72 from 80 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

The final outcome is 17555.833, with a leftover of 0.0008.