266507 ÷ 21 
Our goal is to divide 266507 by 21.

Let's proceed to step 1:
2 divided by 21 is 0 with a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Fetch the next digit (6) from the dividend, attach it to 2 and continue: 26 / 21

Step 2:
26 divided by 21 is 1 with a remainder of 5.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 21 from 26, we get 5.
Include the next digit (6) from the dividend after 5, then repeat: 56 / 21

Let's proceed to step 3:
When dividing 56 by 21, we get 2 with a remainder of 14.
The next digit of our result is 2. 
Result so far: 12.0
If we take 42 away from 56, we end up with 14.
Append the next digit (5) from the dividend to 14 and continue with: 145 / 21

Step 4:
21 can be fit into 145 6 times, resulting in a remainder of 19.
The next digit of our result is 6. 
Result so far: 126.0
Subtracting 126 from 145 leaves us with 19.
Append the next digit (0) from the dividend to 19 and continue with: 190 / 21

Let's proceed to step 5:
If we divide 190 by 21, we get 9 and a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 1269.0
If we subtract 189 from 190, we get 1.
Fetch the next digit (7) from the dividend, attach it to 1 and continue: 17 / 21

Moving on to step 6:
17 divided by 21 is 0 with a remainder of 17.
Put 0 as the next digit of the answer. 
Result so far: 12690.0
Subtracting 0 from 17 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.

On to step 7:
21 can be fit into 170 8 times, resulting in a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 12690.8
The remainder is 2 after subtracting 168 from 170.
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 8:
The number 21 fits into 20 0 times, leaving a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 12690.8
If we take 0 away from 20, we end up 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 9:
200 divided by 21 is 9 with a remainder of 11.
Record the quotient 9 as the next digit in the result. 
Result so far: 12690.809
If we take 189 away from 200, we end up with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 10:
When dividing 110 by 21, we get 5 with a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 12690.8095
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.

Advancing to step 11:
21 can be fit into 50 2 times, resulting in a remainder of 8.
Use 2 as the next digit of our solution. 
Result so far: 12690.80952
If we take 42 away from 50, we end up 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 12:
When dividing 80 by 21, we get 3 with a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 12690.809523
Subtract 63 from 80 to get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Let's proceed to step 13:
170 divided by 21 is 8 with a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 12690.8095238
Subtracting 168 from 170 leaves us 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.

Step 14:
If we divide 20 by 21, we get 0 and a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 12690.8095238
If we take 0 away from 20, we end up 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.

Our division results in 12690.8095238 with a remaining 2e-08.