51628910 ÷ 646 
The aim is to understand the frequency of 646 in 51628910.

Moving on to step 1:
646 goes into 5 0 times with a remainder of 5.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 5 to get 5.
Grab the next digit (1) from the dividend, add it to 5, then carry on: 51 / 646

Going ahead to step 2:
When dividing 51 by 646, we get 0 with a remainder of 51.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 51, we end up with 51.
Append the next digit (6) from the dividend to 51 and continue with: 516 / 646

Moving on to step 3:
516 divided by 646 is 0 with a remainder of 516.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 516, we end up with 516.
Include the next digit (2) from the dividend after 516, then repeat: 5162 / 646

Going ahead to step 4:
The number 646 fits into 5162 7 times, leaving a remainder of 640.
Use 7 as the next digit of our solution. 
Result so far: 7.0
If we subtract 4522 from 5162, we get 640.
Fetch the next digit (8) from the dividend, attach it to 640 and continue: 6408 / 646

Let's proceed to step 5:
6408 divided by 646 is 9 with a remainder of 594.
The number 9 becomes the next digit in our result. 
Result so far: 79.0
The remainder is 594 after subtracting 5814 from 6408.
Append the next digit (9) from the dividend to 594 and continue with: 5949 / 646

Let's proceed to step 6:
5949 divided by 646 is 9 with a remainder of 135.
Use 9 as the next digit of our solution. 
Result so far: 799.0
Subtract 5814 from 5949 to get 135.
Bring next digit (1) of the dividend behind the 135 and repeat the process: 1351 / 646

Step 7:
The number 646 fits into 1351 2 times, leaving a remainder of 59.
The number 2 becomes the next digit in our result. 
Result so far: 7992.0
The remainder is 59 after subtracting 1292 from 1351.
Append the next digit (0) from the dividend to 59 and continue with: 590 / 646

On to step 8:
646 goes into 590 0 times with a remainder of 590.
The next digit of our result is 0. 
Result so far: 79920.0
Subtracting 0 from 590 leaves us with 590.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5900, and continue the process.

Moving on to step 9:
646 goes into 5900 9 times with a remainder of 86.
The number 9 becomes the next digit in our result. 
Result so far: 79920.9
If we subtract 5814 from 5900, we get 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

On to step 10:
If we divide 860 by 646, we get 1 and a remainder of 214.
The number 1 becomes the next digit in our result. 
Result so far: 79920.91
Subtract 646 from 860 to get 214.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2140, and continue the process.

On to step 11:
The number 646 fits into 2140 3 times, leaving a remainder of 202.
Use 3 as the next digit of our solution. 
Result so far: 79920.913
If we subtract 1938 from 2140, we get 202.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2020, and continue the process.

On to step 12:
646 can be fit into 2020 3 times, resulting in a remainder of 82.
Write down 3 as next digit of the result. 
Result so far: 79920.9133
Deduct 1938 from 2020 and we're left with 82.
Since there are no more digits in the dividend, we add a zero to the remainder making it 820, and continue the process.

In conclusion, the division gives 79920.9133 with a balance of 0.00082.