We're dividing 693561 by 51 
The aim is to understand the frequency of 51 in 693561.

On to step 1:
When dividing 6 by 51, we get 0 with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Fetch the next digit (9) from the dividend, attach it to 6 and continue: 69 / 51

Let's proceed to step 2:
The number 51 fits into 69 1 times, leaving a remainder of 18.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we take 51 away from 69, we end up with 18.
Append the next digit (3) from the dividend to 18 and continue with: 183 / 51

Moving on to step 3:
If we divide 183 by 51, we get 3 and a remainder of 30.
Use 3 as the next digit of our solution. 
Result so far: 13.0
The remainder is 30 after subtracting 153 from 183.
Include the next digit (5) from the dividend after 30, then repeat: 305 / 51

Advancing to step 4:
51 goes into 305 5 times with a remainder of 50.
Write down 5 as next digit of the result. 
Result so far: 135.0
If we take 255 away from 305, we end up with 50.
Include the next digit (6) from the dividend after 50, then repeat: 506 / 51

On to step 5:
506 divided by 51 is 9 with a remainder of 47.
The next digit of our result is 9. 
Result so far: 1359.0
The remainder is 47 after subtracting 459 from 506.
Grab the next digit (1) from the dividend, add it to 47, then carry on: 471 / 51

Step 6:
51 can be fit into 471 9 times, resulting in a remainder of 12.
The number 9 becomes the next digit in our result. 
Result so far: 13599.0
Deduct 459 from 471 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 7:
The number 51 fits into 120 2 times, leaving a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 13599.2
Subtracting 102 from 120 leaves us with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 8:
51 can be fit into 180 3 times, resulting in a remainder of 27.
Write down 3 as next digit of the result. 
Result so far: 13599.23
Subtracting 153 from 180 leaves us 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:
When dividing 270 by 51, we get 5 with a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 13599.235
If we subtract 255 from 270, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Advancing to step 10:
150 divided by 51 is 2 with a remainder of 48.
The number 2 becomes the next digit in our result. 
Result so far: 13599.2352
The remainder is 48 after subtracting 102 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Advancing to step 11:
The number 51 fits into 480 9 times, leaving a remainder of 21.
The number 9 becomes the next digit in our result. 
Result so far: 13599.23529
Subtracting 459 from 480 leaves us with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Advancing to step 12:
51 goes into 210 4 times with a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 13599.235294
If we subtract 204 from 210, we 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.

Advancing to step 13:
51 goes into 60 1 times with a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 13599.2352941
Subtract 51 from 60 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 14:
If we divide 90 by 51, we get 1 and a remainder of 39.
The number 1 becomes the next digit in our result. 
Result so far: 13599.23529411
Subtract 51 from 90 to get 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

The quotient of the division is 13599.23529411, and the remainder is 3.9e-08.