We look at the division of 21750631 by 213 
The aim is to understand the frequency of 213 in 21750631.

On to step 1:
The number 213 fits into 2 0 times, leaving a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Fetch the next digit (1) from the dividend, attach it to 2 and continue: 21 / 213

Step 2:
21 divided by 213 is 0 with a remainder of 21.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 21, we end up with 21.
Bring next digit (7) of the dividend behind the 21 and repeat the process: 217 / 213

On to step 3:
If we divide 217 by 213, we get 1 and a remainder of 4.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Deduct 213 from 217 and we're left with 4.
Fetch the next digit (5) from the dividend, attach it to 4 and continue: 45 / 213

On to step 4:
If we divide 45 by 213, we get 0 and a remainder of 45.
Put 0 as the next digit of the answer. 
Result so far: 10.0
Deduct 0 from 45 and we're left with 45.
Grab the next digit (0) from the dividend, add it to 45, then carry on: 450 / 213

Step 5:
When dividing 450 by 213, we get 2 with a remainder of 24.
The next digit of our result is 2. 
Result so far: 102.0
If we take 426 away from 450, we end up with 24.
Include the next digit (6) from the dividend after 24, then repeat: 246 / 213

Going ahead to step 6:
246 divided by 213 is 1 with a remainder of 33.
The next digit of our result is 1. 
Result so far: 1021.0
Subtract 213 from 246 to get 33.
Grab the next digit (3) from the dividend, add it to 33, then carry on: 333 / 213

Let's proceed to step 7:
The number 213 fits into 333 1 times, leaving a remainder of 120.
Use 1 as the next digit of our solution. 
Result so far: 10211.0
The remainder is 120 after subtracting 213 from 333.
Fetch the next digit (1) from the dividend, attach it to 120 and continue: 1201 / 213

Moving on to step 8:
The number 213 fits into 1201 5 times, leaving a remainder of 136.
Use 5 as the next digit of our solution. 
Result so far: 102115.0
Deduct 1065 from 1201 and we're left with 136.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1360, and continue the process.

Moving on to step 9:
If we divide 1360 by 213, we get 6 and a remainder of 82.
Use 6 as the next digit of our solution. 
Result so far: 102115.6
Deduct 1278 from 1360 and we're left with 82.
Since there are no more digits in the dividend, we add a zero to the remainder making it 820, and continue the process.

Let's proceed to step 10:
When dividing 820 by 213, we get 3 with a remainder of 181.
Record the quotient 3 as the next digit in the result. 
Result so far: 102115.63
Deduct 639 from 820 and we're left with 181.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1810, and continue the process.

Step 11:
213 goes into 1810 8 times with a remainder of 106.
Put 8 as the next digit of the answer. 
Result so far: 102115.638
If we take 1704 away from 1810, we end up with 106.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1060, and continue the process.

Let's proceed to step 12:
213 can be fit into 1060 4 times, resulting in a remainder of 208.
Record the quotient 4 as the next digit in the result. 
Result so far: 102115.6384
Deduct 852 from 1060 and we're left with 208.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2080, and continue the process.

Let's proceed to step 13:
213 goes into 2080 9 times with a remainder of 163.
Put 9 as the next digit of the answer. 
Result so far: 102115.63849
The remainder is 163 after subtracting 1917 from 2080.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1630, and continue the process.

Advancing to step 14:
When dividing 1630 by 213, we get 7 with a remainder of 139.
The number 7 becomes the next digit in our result. 
Result so far: 102115.638497
Subtracting 1491 from 1630 leaves us with 139.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1390, and continue the process.

Going ahead to step 15:
When dividing 1390 by 213, we get 6 with a remainder of 112.
Use 6 as the next digit of our solution. 
Result so far: 102115.6384976
If we take 1278 away from 1390, we end up with 112.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1120, and continue the process.

Going ahead to step 16:
213 goes into 1120 5 times with a remainder of 55.
Record the quotient 5 as the next digit in the result. 
Result so far: 102115.63849765
If we subtract 1065 from 1120, we get 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

The quotient of the division is 102115.63849765, and the remainder is 5.5e-08.