We're dividing 21512321 by 300 
We want to divide 21512321 by 300.

Moving on to step 1:
If we divide 2 by 300, we get 0 and a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 300

Moving on to step 2:
21 divided by 300 is 0 with a remainder of 21.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 21, we get 21.
Take the next digit (5) from the dividend and append it to 21, then repeat: 215 / 300

Let's proceed to step 3:
When dividing 215 by 300, we get 0 with a remainder of 215.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 215 after subtracting 0 from 215.
Fetch the next digit (1) from the dividend, attach it to 215 and continue: 2151 / 300

Step 4:
300 can be fit into 2151 7 times, resulting in a remainder of 51.
The next digit of our result is 7. 
Result so far: 7.0
If we subtract 2100 from 2151, we get 51.
Take the next digit (2) from the dividend and append it to 51, then repeat: 512 / 300

On to step 5:
When dividing 512 by 300, we get 1 with a remainder of 212.
Use 1 as the next digit of our solution. 
Result so far: 71.0
The remainder is 212 after subtracting 300 from 512.
Fetch the next digit (3) from the dividend, attach it to 212 and continue: 2123 / 300

Going ahead to step 6:
If we divide 2123 by 300, we get 7 and a remainder of 23.
Use 7 as the next digit of our solution. 
Result so far: 717.0
Subtracting 2100 from 2123 leaves us with 23.
Take the next digit (2) from the dividend and append it to 23, then repeat: 232 / 300

Moving on to step 7:
300 goes into 232 0 times with a remainder of 232.
The number 0 becomes the next digit in our result. 
Result so far: 7170.0
If we subtract 0 from 232, we get 232.
Grab the next digit (1) from the dividend, add it to 232, then carry on: 2321 / 300

Step 8:
If we divide 2321 by 300, we get 7 and a remainder of 221.
Put 7 as the next digit of the answer. 
Result so far: 71707.0
Deduct 2100 from 2321 and we're left with 221.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2210, and continue the process.

Moving on to step 9:
When dividing 2210 by 300, we get 7 with a remainder of 110.
Use 7 as the next digit of our solution. 
Result so far: 71707.7
Subtracting 2100 from 2210 leaves us with 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1100, and continue the process.

Advancing to step 10:
1100 divided by 300 is 3 with a remainder of 200.
The number 3 becomes the next digit in our result. 
Result so far: 71707.73
If we subtract 900 from 1100, we get 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Advancing to step 11:
When dividing 2000 by 300, we get 6 with a remainder of 200.
The next digit of our result is 6. 
Result so far: 71707.736
Subtracting 1800 from 2000 leaves us with 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Step 12:
300 can be fit into 2000 6 times, resulting in a remainder of 200.
Record the quotient 6 as the next digit in the result. 
Result so far: 71707.7366
Subtracting 1800 from 2000 leaves us with 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

In conclusion, the division gives 71707.7366 with a balance of 0.002.