88151631 ÷ 7 
The aim is to understand the frequency of 7 in 88151631.

Going ahead to step 1:
When dividing 8 by 7, we get 1 with a remainder of 1.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 7 from 8 and we're left with 1.
Fetch the next digit (8) from the dividend, attach it to 1 and continue: 18 / 7

Step 2:
7 goes into 18 2 times with a remainder of 4.
The next digit of our result is 2. 
Result so far: 12.0
Subtract 14 from 18 to get 4.
Take the next digit (1) from the dividend and append it to 4, then repeat: 41 / 7

Let's proceed to step 3:
If we divide 41 by 7, we get 5 and a remainder of 6.
Use 5 as the next digit of our solution. 
Result so far: 125.0
If we subtract 35 from 41, we get 6.
Grab the next digit (5) from the dividend, add it to 6, then carry on: 65 / 7

Let's proceed to step 4:
When dividing 65 by 7, we get 9 with a remainder of 2.
Write down 9 as next digit of the result. 
Result so far: 1259.0
Subtract 63 from 65 to get 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 7

Going ahead to step 5:
If we divide 21 by 7, we get 3 and a remainder of 0.
Write down 3 as next digit of the result. 
Result so far: 12593.0
If we take 21 away from 21, we end up with 0.
Take the next digit (6) from the dividend and append it to 0, then repeat: 6 / 7

Moving on to step 6:
If we divide 6 by 7, we get 0 and a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 125930.0
If we take 0 away from 6, we end up with 6.
Include the next digit (3) from the dividend after 6, then repeat: 63 / 7

Let's proceed to step 7:
63 divided by 7 is 9 with a remainder of 0.
Put 9 as the next digit of the answer. 
Result so far: 1259309.0
Subtract 63 from 63 to get 0.
Append the next digit (1) from the dividend to 0 and continue with: 1 / 7

Let's proceed to step 8:
When dividing 1 by 7, we get 0 with a remainder of 1.
The next digit of our result is 0. 
Result so far: 12593090.0
If we take 0 away from 1, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 9:
The number 7 fits into 10 1 times, leaving a remainder of 3.
The number 1 becomes the next digit in our result. 
Result so far: 12593090.1
If we subtract 7 from 10, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 10:
If we divide 30 by 7, we get 4 and a remainder of 2.
Use 4 as the next digit of our solution. 
Result so far: 12593090.14
If we take 28 away from 30, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 11:
7 can be fit into 20 2 times, resulting in a remainder of 6.
The number 2 becomes the next digit in our result. 
Result so far: 12593090.142
Subtract 14 from 20 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Let's proceed to step 12:
7 goes into 60 8 times with a remainder of 4.
Record the quotient 8 as the next digit in the result. 
Result so far: 12593090.1428
If we take 56 away from 60, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 13:
7 can be fit into 40 5 times, resulting in a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 12593090.14285
If we subtract 35 from 40, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 14:
When dividing 50 by 7, we get 7 with a remainder of 1.
The number 7 becomes the next digit in our result. 
Result so far: 12593090.142857
Subtracting 49 from 50 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 15:
10 divided by 7 is 1 with a remainder of 3.
Put 1 as the next digit of the answer. 
Result so far: 12593090.1428571
If we take 7 away from 10, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 16:
7 goes into 30 4 times with a remainder of 2.
The next digit of our result is 4. 
Result so far: 12593090.14285714
If we subtract 28 from 30, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The final result is 12593090.14285714 with a remainder of 2e-09.