421380 ÷ 24 
We want to figure out the number of times 421380 can be divided by 24.

On to step 1:
The number 24 fits into 4 0 times, leaving a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Grab the next digit (2) from the dividend, add it to 4, then carry on: 42 / 24

Going ahead to step 2:
24 goes into 42 1 times with a remainder of 18.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we take 24 away from 42, we end up with 18.
Bring next digit (1) of the dividend behind the 18 and repeat the process: 181 / 24

Advancing to step 3:
24 goes into 181 7 times with 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.
Fetch the next digit (3) from the dividend, attach it to 13 and continue: 133 / 24

Step 4:
24 goes into 133 5 times with a remainder of 13.
Write down 5 as next digit of the result. 
Result so far: 175.0
Subtracting 120 from 133 leaves us with 13.
Include the next digit (8) from the dividend after 13, then repeat: 138 / 24

Going ahead to step 5:
If we divide 138 by 24, we get 5 and a remainder of 18.
Record the quotient 5 as the next digit in the result. 
Result so far: 1755.0
If we subtract 120 from 138, we get 18.
Take the next digit (0) from the dividend and append it to 18, then repeat: 180 / 24

Step 6:
180 divided by 24 is 7 with a remainder of 12.
Write down 7 as next digit of the result. 
Result so far: 17557.0
If we take 168 away from 180, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 7:
The number 24 fits into 120 5 times, leaving a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 17557.5
If we subtract 120 from 120, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 8:
24 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 17557.5
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 9:
If we divide 0 by 24, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 17557.5
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 17557.5 with a remaining 0.0.