We're dividing 25911222 by 210 
The aim is to understand the frequency of 210 in 25911222.

Moving on to step 1:
The number 210 fits into 2 0 times, leaving a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Append the next digit (5) from the dividend to 2 and continue with: 25 / 210

Advancing to step 2:
If we divide 25 by 210, we get 0 and a remainder of 25.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 25, we get 25.
Bring next digit (9) of the dividend behind the 25 and repeat the process: 259 / 210

Step 3:
When dividing 259 by 210, we get 1 with a remainder of 49.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Deduct 210 from 259 and we're left with 49.
Fetch the next digit (1) from the dividend, attach it to 49 and continue: 491 / 210

Let's proceed to step 4:
The number 210 fits into 491 2 times, leaving a remainder of 71.
Put 2 as the next digit of the answer. 
Result so far: 12.0
If we subtract 420 from 491, we get 71.
Include the next digit (1) from the dividend after 71, then repeat: 711 / 210

Advancing to step 5:
210 goes into 711 3 times with a remainder of 81.
Put 3 as the next digit of the answer. 
Result so far: 123.0
Deduct 630 from 711 and we're left with 81.
Fetch the next digit (2) from the dividend, attach it to 81 and continue: 812 / 210

On to step 6:
If we divide 812 by 210, we get 3 and a remainder of 182.
The number 3 becomes the next digit in our result. 
Result so far: 1233.0
Deduct 630 from 812 and we're left with 182.
Take the next digit (2) from the dividend and append it to 182, then repeat: 1822 / 210

Moving on to step 7:
210 goes into 1822 8 times with a remainder of 142.
The next digit of our result is 8. 
Result so far: 12338.0
Deduct 1680 from 1822 and we're left with 142.
Include the next digit (2) from the dividend after 142, then repeat: 1422 / 210

Advancing to step 8:
When dividing 1422 by 210, we get 6 with a remainder of 162.
Write down 6 as next digit of the result. 
Result so far: 123386.0
If we subtract 1260 from 1422, we get 162.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1620, and continue the process.

Advancing to step 9:
210 can be fit into 1620 7 times, resulting in a remainder of 150.
Record the quotient 7 as the next digit in the result. 
Result so far: 123386.7
If we take 1470 away from 1620, we end up with 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

Going ahead to step 10:
The number 210 fits into 1500 7 times, leaving a remainder of 30.
Record the quotient 7 as the next digit in the result. 
Result so far: 123386.77
If we subtract 1470 from 1500, we get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

The quotient of the division is 123386.77, and the remainder is 0.03.