We look at the division of 409420 by 1 
The aim is to understand the frequency of 1 in 409420.

Let's proceed to step 1:
4 divided by 1 is 4 with a remainder of 0.
Write down 4 as next digit of the result. 
Result so far: 4.0
If we take 4 away from 4, we end up with 0.
Append the next digit (0) from the dividend to 0 and continue with: 0 / 1

On to step 2:
0 divided by 1 is 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 40.0
If we subtract 0 from 0, we get 0.
Grab the next digit (9) from the dividend, add it to 0, then carry on: 9 / 1

On to step 3:
1 can be fit into 9 9 times, resulting in a remainder of 0.
The next digit of our result is 9. 
Result so far: 409.0
The remainder is 0 after subtracting 9 from 9.
Fetch the next digit (4) from the dividend, attach it to 0 and continue: 4 / 1

Let's proceed to step 4:
The number 1 fits into 4 4 times, leaving a remainder of 0.
Put 4 as the next digit of the answer. 
Result so far: 4094.0
If we take 4 away from 4, we end up with 0.
Take the next digit (2) from the dividend and append it to 0, then repeat: 2 / 1

Going ahead to step 5:
1 can be fit into 2 2 times, resulting in a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 40942.0
Subtract 2 from 2 to get 0.
Take the next digit (0) from the dividend and append it to 0, then repeat: 0 / 1

Step 6:
1 can be fit into 0 0 times, resulting in a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 409420.0
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 7:
1 can be fit into 0 0 times, resulting in a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 409420.0
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 8:
0 divided by 1 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 409420.0
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 409420.0 with a remaining 0.0.