We look at the division of 971584 by 21 
We want to figure out the number of times 971584 can be divided by 21.

Advancing to step 1:
21 goes into 9 0 times with a remainder of 9.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 9 and we're left with 9.
Append the next digit (7) from the dividend to 9 and continue with: 97 / 21

Let's proceed to step 2:
21 can be fit into 97 4 times, resulting in a remainder of 13.
Put 4 as the next digit of the answer. 
Result so far: 4.0
If we take 84 away from 97, we end up with 13.
Take the next digit (1) from the dividend and append it to 13, then repeat: 131 / 21

Step 3:
21 goes into 131 6 times with a remainder of 5.
Write down 6 as next digit of the result. 
Result so far: 46.0
Deduct 126 from 131 and we're left with 5.
Fetch the next digit (5) from the dividend, attach it to 5 and continue: 55 / 21

Moving on to step 4:
21 goes into 55 2 times with a remainder of 13.
The next digit of our result is 2. 
Result so far: 462.0
If we take 42 away from 55, we end up with 13.
Include the next digit (8) from the dividend after 13, then repeat: 138 / 21

Let's proceed to step 5:
The number 21 fits into 138 6 times, leaving a remainder of 12.
Use 6 as the next digit of our solution. 
Result so far: 4626.0
Subtracting 126 from 138 leaves us with 12.
Include the next digit (4) from the dividend after 12, then repeat: 124 / 21

On to step 6:
When dividing 124 by 21, we get 5 with a remainder of 19.
Record the quotient 5 as the next digit in the result. 
Result so far: 46265.0
The remainder is 19 after subtracting 105 from 124.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Step 7:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 46265.9
If we take 189 away from 190, 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.

Step 8:
When dividing 10 by 21, we get 0 with a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 46265.9
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 9:
21 can be fit into 100 4 times, resulting in a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 46265.904
Deduct 84 from 100 and we're left 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 10:
21 can be fit into 160 7 times, resulting in a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 46265.9047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 11:
When dividing 130 by 21, we get 6 with a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 46265.90476
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 12:
40 divided by 21 is 1 with a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 46265.904761
If we subtract 21 from 40, we 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.

Let's proceed to step 13:
The number 21 fits into 190 9 times, leaving a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 46265.9047619
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.

Going ahead to step 14:
10 divided by 21 is 0 with a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 46265.9047619
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.

After the division, we end up with 46265.9047619 and a remainder of 1e-08.