10487151 ÷ 409 
The aim is to understand the frequency of 409 in 10487151.

Advancing to step 1:
409 can be fit into 1 0 times, resulting in a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Fetch the next digit (0) from the dividend, attach it to 1 and continue: 10 / 409

Moving on to step 2:
When dividing 10 by 409, we get 0 with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 10 and we're left with 10.
Take the next digit (4) from the dividend and append it to 10, then repeat: 104 / 409

Step 3:
If we divide 104 by 409, we get 0 and a remainder of 104.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 104 to get 104.
Append the next digit (8) from the dividend to 104 and continue with: 1048 / 409

Going ahead to step 4:
The number 409 fits into 1048 2 times, leaving a remainder of 230.
Use 2 as the next digit of our solution. 
Result so far: 2.0
If we subtract 818 from 1048, we get 230.
Fetch the next digit (7) from the dividend, attach it to 230 and continue: 2307 / 409

Advancing to step 5:
409 can be fit into 2307 5 times, resulting in a remainder of 262.
Write down 5 as next digit of the result. 
Result so far: 25.0
The remainder is 262 after subtracting 2045 from 2307.
Bring next digit (1) of the dividend behind the 262 and repeat the process: 2621 / 409

On to step 6:
If we divide 2621 by 409, we get 6 and a remainder of 167.
Write down 6 as next digit of the result. 
Result so far: 256.0
The remainder is 167 after subtracting 2454 from 2621.
Append the next digit (5) from the dividend to 167 and continue with: 1675 / 409

Moving on to step 7:
409 can be fit into 1675 4 times, resulting in a remainder of 39.
The number 4 becomes the next digit in our result. 
Result so far: 2564.0
Subtract 1636 from 1675 to get 39.
Grab the next digit (1) from the dividend, add it to 39, then carry on: 391 / 409

Going ahead to step 8:
When dividing 391 by 409, we get 0 with a remainder of 391.
The next digit of our result is 0. 
Result so far: 25640.0
Subtracting 0 from 391 leaves us with 391.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3910, and continue the process.

Step 9:
When dividing 3910 by 409, we get 9 with a remainder of 229.
Use 9 as the next digit of our solution. 
Result so far: 25640.9
If we take 3681 away from 3910, we end up with 229.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2290, and continue the process.

Step 10:
If we divide 2290 by 409, we get 5 and a remainder of 245.
The number 5 becomes the next digit in our result. 
Result so far: 25640.95
Deduct 2045 from 2290 and we're left with 245.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2450, and continue the process.

Let's proceed to step 11:
409 goes into 2450 5 times with a remainder of 405.
Use 5 as the next digit of our solution. 
Result so far: 25640.955
Deduct 2045 from 2450 and we're left with 405.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4050, and continue the process.

The quotient of the division is 25640.955, and the remainder is 0.0405.