We're dividing 453484 by 21 
We want to figure out the number of times 453484 can be divided by 21.

Let's proceed to step 1:
21 can be fit into 4 0 times, resulting in a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Grab the next digit (5) from the dividend, add it to 4, then carry on: 45 / 21

Let's proceed to step 2:
45 divided by 21 is 2 with a remainder of 3.
The next digit of our result is 2. 
Result so far: 2.0
If we subtract 42 from 45, we get 3.
Take the next digit (3) from the dividend and append it to 3, then repeat: 33 / 21

Advancing to step 3:
21 can be fit into 33 1 times, resulting in a remainder of 12.
Use 1 as the next digit of our solution. 
Result so far: 21.0
If we take 21 away from 33, we end up with 12.
Grab the next digit (4) from the dividend, add it to 12, then carry on: 124 / 21

On to step 4:
21 can be fit into 124 5 times, resulting in a remainder of 19.
Use 5 as the next digit of our solution. 
Result so far: 215.0
Subtracting 105 from 124 leaves us with 19.
Append the next digit (8) from the dividend to 19 and continue with: 198 / 21

Moving on to step 5:
21 goes into 198 9 times with a remainder of 9.
Use 9 as the next digit of our solution. 
Result so far: 2159.0
If we take 189 away from 198, we end up with 9.
Append the next digit (4) from the dividend to 9 and continue with: 94 / 21

Let's proceed to step 6:
21 goes into 94 4 times with a remainder of 10.
Record the quotient 4 as the next digit in the result. 
Result so far: 21594.0
The remainder is 10 after subtracting 84 from 94.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 7:
The number 21 fits into 100 4 times, leaving a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 21594.4
If we take 84 away from 100, we end up 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.

On to step 8:
The number 21 fits into 160 7 times, leaving a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 21594.47
Subtracting 147 from 160 leaves us with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Step 9:
21 goes into 130 6 times with a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 21594.476
If we subtract 126 from 130, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 10:
The number 21 fits into 40 1 times, leaving a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 21594.4761
Subtract 21 from 40 to get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Step 11:
21 goes into 190 9 times with a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 21594.47619
Deduct 189 from 190 and we're left 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 12:
When dividing 10 by 21, we get 0 with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 21594.47619
If we take 0 away from 10, 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.

On to step 13:
When dividing 100 by 21, we get 4 with a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 21594.4761904
If we take 84 away from 100, we end up 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.

Let's proceed to step 14:
The number 21 fits into 160 7 times, leaving a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 21594.47619047
The remainder is 13 after subtracting 147 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

The final outcome is 21594.47619047, with a leftover of 1.3e-08.