Let's divide 71603983 by 1
The aim is to understand the frequency of 1 in 71603983.

On to step 1:
7 divided by 1 is 7 with a remainder of 0.
Put 7 as the next digit of the answer. 
Result so far: 7.0
If we take 7 away from 7, we end up with 0.
Include the next digit (1) from the dividend after 0, then repeat: 1 / 1

Let's proceed to step 2:
When dividing 1 by 1, we get 1 with a remainder of 0.
Put 1 as the next digit of the answer. 
Result so far: 71.0
If we take 1 away from 1, we end up with 0.
Fetch the next digit (6) from the dividend, attach it to 0 and continue: 6 / 1

On to step 3:
6 divided by 1 is 6 with a remainder of 0.
The number 6 becomes the next digit in our result. 
Result so far: 716.0
The remainder is 0 after subtracting 6 from 6.
Take the next digit (0) from the dividend and append it to 0, then repeat: 0 / 1

Advancing to step 4:
If we divide 0 by 1, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 7160.0
Deduct 0 from 0 and we're left with 0.
Include the next digit (3) from the dividend after 0, then repeat: 3 / 1

On to step 5:
If we divide 3 by 1, we get 3 and a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 71603.0
The remainder is 0 after subtracting 3 from 3.
Append the next digit (9) from the dividend to 0 and continue with: 9 / 1

Going ahead to step 6:
The number 1 fits into 9 9 times, leaving a remainder of 0.
Use 9 as the next digit of our solution. 
Result so far: 716039.0
The remainder is 0 after subtracting 9 from 9.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 1

Moving on to step 7:
The number 1 fits into 8 8 times, leaving a remainder of 0.
The number 8 becomes the next digit in our result. 
Result so far: 7160398.0
If we subtract 8 from 8, we get 0.
Append the next digit (3) from the dividend to 0 and continue with: 3 / 1

Advancing to step 8:
1 goes into 3 3 times with a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 71603983.0
If we subtract 3 from 3, 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 9:
When dividing 0 by 1, we get 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 71603983.0
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.

Going ahead to step 10:
1 goes into 0 0 times with a remainder of 0.
The next digit of our result is 0. 
Result so far: 71603983.0
If we take 0 away from 0, we end up 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.

Our division results in 71603983.0 with a remaining 0.0.