We divide 42986264 by 409
The aim is to understand the frequency of 409 in 42986264.

On to step 1:
When dividing 4 by 409, we get 0 with a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 409

On to step 2:
When dividing 42 by 409, we get 0 with a remainder of 42.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 42, we get 42.
Fetch the next digit (9) from the dividend, attach it to 42 and continue: 429 / 409

Advancing to step 3:
When dividing 429 by 409, we get 1 with a remainder of 20.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtract 409 from 429 to get 20.
Grab the next digit (8) from the dividend, add it to 20, then carry on: 208 / 409

Let's proceed to step 4:
If we divide 208 by 409, we get 0 and a remainder of 208.
The next digit of our result is 0. 
Result so far: 10.0
If we take 0 away from 208, we end up with 208.
Grab the next digit (6) from the dividend, add it to 208, then carry on: 2086 / 409

Moving on to step 5:
2086 divided by 409 is 5 with a remainder of 41.
Put 5 as the next digit of the answer. 
Result so far: 105.0
Deduct 2045 from 2086 and we're left with 41.
Bring next digit (2) of the dividend behind the 41 and repeat the process: 412 / 409

Moving on to step 6:
When dividing 412 by 409, we get 1 with a remainder of 3.
The number 1 becomes the next digit in our result. 
Result so far: 1051.0
If we subtract 409 from 412, we get 3.
Include the next digit (6) from the dividend after 3, then repeat: 36 / 409

Step 7:
When dividing 36 by 409, we get 0 with a remainder of 36.
The next digit of our result is 0. 
Result so far: 10510.0
The remainder is 36 after subtracting 0 from 36.
Fetch the next digit (4) from the dividend, attach it to 36 and continue: 364 / 409

Advancing to step 8:
If we divide 364 by 409, we get 0 and a remainder of 364.
The number 0 becomes the next digit in our result. 
Result so far: 105100.0
Deduct 0 from 364 and we're left with 364.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3640, and continue the process.

Advancing to step 9:
When dividing 3640 by 409, we get 8 with a remainder of 368.
Record the quotient 8 as the next digit in the result. 
Result so far: 105100.8
Subtract 3272 from 3640 to get 368.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3680, and continue the process.

On to step 10:
If we divide 3680 by 409, we get 8 and a remainder of 408.
Write down 8 as next digit of the result. 
Result so far: 105100.88
If we take 3272 away from 3680, we end up with 408.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4080, and continue the process.

The final outcome is 105100.88, with a leftover of 0.408.