143236 ÷ 21 
Our goal is to divide 143236 by 21.

Moving on to step 1:
The number 21 fits into 1 0 times, leaving a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (4) from the dividend to 1 and continue with: 14 / 21

Moving on to step 2:
The number 21 fits into 14 0 times, leaving a remainder of 14.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 14 after subtracting 0 from 14.
Bring next digit (3) of the dividend behind the 14 and repeat the process: 143 / 21

Moving on to step 3:
If we divide 143 by 21, we get 6 and a remainder of 17.
Use 6 as the next digit of our solution. 
Result so far: 6.0
Subtracting 126 from 143 leaves us with 17.
Include the next digit (2) from the dividend after 17, then repeat: 172 / 21

Moving on to step 4:
The number 21 fits into 172 8 times, leaving a remainder of 4.
The next digit of our result is 8. 
Result so far: 68.0
Subtract 168 from 172 to get 4.
Take the next digit (3) from the dividend and append it to 4, then repeat: 43 / 21

Advancing to step 5:
If we divide 43 by 21, we get 2 and a remainder of 1.
The next digit of our result is 2. 
Result so far: 682.0
The remainder is 1 after subtracting 42 from 43.
Grab the next digit (6) from the dividend, add it to 1, then carry on: 16 / 21

Moving on to step 6:
The number 21 fits into 16 0 times, leaving a remainder of 16.
Put 0 as the next digit of the answer. 
Result so far: 6820.0
If we take 0 away from 16, 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 7:
The number 21 fits into 160 7 times, leaving a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 6820.7
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.

Moving on to step 8:
21 can be fit into 130 6 times, resulting in a remainder of 4.
The next digit of our result is 6. 
Result so far: 6820.76
Subtracting 126 from 130 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 9:
21 goes into 40 1 times with a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 6820.761
Subtracting 21 from 40 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Moving on to step 10:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 6820.7619
The remainder is 1 after subtracting 189 from 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 11:
If we divide 10 by 21, we get 0 and a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 6820.7619
If we subtract 0 from 10, we 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.

On to step 12:
100 divided by 21 is 4 with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 6820.761904
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.

Let's proceed to step 13:
If we divide 160 by 21, we get 7 and a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 6820.7619047
If we take 147 away from 160, we end up 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.

Advancing to step 14:
130 divided by 21 is 6 with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 6820.76190476
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.

The final outcome is 6820.76190476, with a leftover of 4e-09.