13583 ÷ 21 
We want to divide 13583 by 21.

Step 1:
If we divide 1 by 21, we get 0 and a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Fetch the next digit (3) from the dividend, attach it to 1 and continue: 13 / 21

Advancing to step 2:
21 goes into 13 0 times with a remainder of 13.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 13 and we're left with 13.
Append the next digit (5) from the dividend to 13 and continue with: 135 / 21

Moving on to step 3:
135 divided by 21 is 6 with a remainder of 9.
Use 6 as the next digit of our solution. 
Result so far: 6.0
If we subtract 126 from 135, we get 9.
Grab the next digit (8) from the dividend, add it to 9, then carry on: 98 / 21

Advancing to step 4:
When dividing 98 by 21, we get 4 with a remainder of 14.
Put 4 as the next digit of the answer. 
Result so far: 64.0
Subtract 84 from 98 to get 14.
Fetch the next digit (3) from the dividend, attach it to 14 and continue: 143 / 21

Let's proceed to step 5:
The number 21 fits into 143 6 times, leaving a remainder of 17.
Use 6 as the next digit of our solution. 
Result so far: 646.0
The remainder is 17 after subtracting 126 from 143.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Advancing to step 6:
If we divide 170 by 21, we get 8 and a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 646.8
If we take 168 away from 170, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 7:
The number 21 fits into 20 0 times, leaving a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 646.8
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Let's proceed to step 8:
If we divide 200 by 21, we get 9 and a remainder of 11.
Use 9 as the next digit of our solution. 
Result so far: 646.809
Subtract 189 from 200 to get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 9:
21 can be fit into 110 5 times, resulting in a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 646.8095
If we subtract 105 from 110, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 10:
When dividing 50 by 21, we get 2 with a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 646.80952
Subtract 42 from 50 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 11:
21 can be fit into 80 3 times, resulting in a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 646.809523
Subtracting 63 from 80 leaves us with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Step 12:
170 divided by 21 is 8 with a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 646.8095238
If we subtract 168 from 170, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 13:
21 can be fit into 20 0 times, resulting in a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 646.8095238
Subtracting 0 from 20 leaves us 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.

The final outcome is 646.8095238, with a leftover of 2e-08.