We're dividing 21508185 by 258 
We want to divide 21508185 by 258.

Going ahead to step 1:
258 can be fit into 2 0 times, resulting in 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.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 258

Advancing to step 2:
258 goes into 21 0 times with a remainder of 21.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 21 leaves us with 21.
Grab the next digit (5) from the dividend, add it to 21, then carry on: 215 / 258

On to step 3:
When dividing 215 by 258, we get 0 with a remainder of 215.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 215, we end up with 215.
Take the next digit (0) from the dividend and append it to 215, then repeat: 2150 / 258

Let's proceed to step 4:
The number 258 fits into 2150 8 times, leaving a remainder of 86.
Put 8 as the next digit of the answer. 
Result so far: 8.0
The remainder is 86 after subtracting 2064 from 2150.
Grab the next digit (8) from the dividend, add it to 86, then carry on: 868 / 258

Step 5:
When dividing 868 by 258, we get 3 with a remainder of 94.
Use 3 as the next digit of our solution. 
Result so far: 83.0
Deduct 774 from 868 and we're left with 94.
Bring next digit (1) of the dividend behind the 94 and repeat the process: 941 / 258

Moving on to step 6:
258 goes into 941 3 times with a remainder of 167.
Write down 3 as next digit of the result. 
Result so far: 833.0
The remainder is 167 after subtracting 774 from 941.
Bring next digit (8) of the dividend behind the 167 and repeat the process: 1678 / 258

Let's proceed to step 7:
When dividing 1678 by 258, we get 6 with a remainder of 130.
Use 6 as the next digit of our solution. 
Result so far: 8336.0
If we subtract 1548 from 1678, we get 130.
Bring next digit (5) of the dividend behind the 130 and repeat the process: 1305 / 258

Advancing to step 8:
258 can be fit into 1305 5 times, resulting in a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 83365.0
Deduct 1290 from 1305 and we're left with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 9:
258 can be fit into 150 0 times, resulting in a remainder of 150.
Use 0 as the next digit of our solution. 
Result so far: 83365.0
If we subtract 0 from 150, we get 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

Let's proceed to step 10:
The number 258 fits into 1500 5 times, leaving a remainder of 210.
Use 5 as the next digit of our solution. 
Result so far: 83365.05
Subtract 1290 from 1500 to get 210.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2100, and continue the process.

Advancing to step 11:
258 can be fit into 2100 8 times, resulting in a remainder of 36.
The next digit of our result is 8. 
Result so far: 83365.058
Subtract 2064 from 2100 to get 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Moving on to step 12:
The number 258 fits into 360 1 times, leaving a remainder of 102.
Record the quotient 1 as the next digit in the result. 
Result so far: 83365.0581
Subtract 258 from 360 to get 102.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1020, and continue the process.

Let's proceed to step 13:
258 goes into 1020 3 times with a remainder of 246.
Record the quotient 3 as the next digit in the result. 
Result so far: 83365.05813
If we subtract 774 from 1020, we get 246.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2460, and continue the process.

Going ahead to step 14:
When dividing 2460 by 258, we get 9 with a remainder of 138.
Write down 9 as next digit of the result. 
Result so far: 83365.058139
Subtracting 2322 from 2460 leaves us with 138.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1380, and continue the process.

Moving on to step 15:
If we divide 1380 by 258, we get 5 and a remainder of 90.
Use 5 as the next digit of our solution. 
Result so far: 83365.0581395
Subtract 1290 from 1380 to get 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Let's proceed to step 16:
258 can be fit into 900 3 times, resulting in a remainder of 126.
Use 3 as the next digit of our solution. 
Result so far: 83365.05813953
If we subtract 774 from 900, we get 126.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1260, and continue the process.

After the division, we end up with 83365.05813953 and a remainder of 1.26e-07.