13987 ÷ 77 
The aim is to understand the frequency of 77 in 13987.

Going ahead to step 1:
77 goes into 1 0 times with a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Fetch the next digit (3) from the dividend, attach it to 1 and continue: 13 / 77

Going ahead to step 2:
77 can be fit into 13 0 times, resulting in a remainder of 13.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 13 leaves us with 13.
Fetch the next digit (9) from the dividend, attach it to 13 and continue: 139 / 77

Step 3:
When dividing 139 by 77, we get 1 with a remainder of 62.
The next digit of our result is 1. 
Result so far: 1.0
Deduct 77 from 139 and we're left with 62.
Include the next digit (8) from the dividend after 62, then repeat: 628 / 77

Step 4:
77 goes into 628 8 times with a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 18.0
Deduct 616 from 628 and we're left with 12.
Grab the next digit (7) from the dividend, add it to 12, then carry on: 127 / 77

Going ahead to step 5:
77 goes into 127 1 times with a remainder of 50.
Write down 1 as next digit of the result. 
Result so far: 181.0
Deduct 77 from 127 and we're left with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Step 6:
500 divided by 77 is 6 with a remainder of 38.
The next digit of our result is 6. 
Result so far: 181.6
The remainder is 38 after subtracting 462 from 500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Advancing to step 7:
77 goes into 380 4 times with a remainder of 72.
Use 4 as the next digit of our solution. 
Result so far: 181.64
If we take 308 away from 380, we end up with 72.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

Let's proceed to step 8:
77 goes into 720 9 times with a remainder of 27.
Write down 9 as next digit of the result. 
Result so far: 181.649
Deduct 693 from 720 and we're left with 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Moving on to step 9:
The number 77 fits into 270 3 times, leaving a remainder of 39.
Record the quotient 3 as the next digit in the result. 
Result so far: 181.6493
Deduct 231 from 270 and we're left with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Advancing to step 10:
If we divide 390 by 77, we get 5 and a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 181.64935
Subtracting 385 from 390 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 11:
77 goes into 50 0 times with a remainder of 50.
Record the quotient 0 as the next digit in the result. 
Result so far: 181.64935
The remainder is 50 after subtracting 0 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Moving on to step 12:
77 goes into 500 6 times with a remainder of 38.
Use 6 as the next digit of our solution. 
Result so far: 181.6493506
If we take 462 away from 500, we end up with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

On to step 13:
If we divide 380 by 77, we get 4 and a remainder of 72.
The number 4 becomes the next digit in our result. 
Result so far: 181.64935064
If we subtract 308 from 380, we get 72.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

After the division, we end up with 181.64935064 and a remainder of 7.2e-08.