43599365 ÷ 561 
The aim is to understand the frequency of 561 in 43599365.

Let's proceed to step 1:
When dividing 4 by 561, we get 0 with a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Fetch the next digit (3) from the dividend, attach it to 4 and continue: 43 / 561

Going ahead to step 2:
When dividing 43 by 561, we get 0 with a remainder of 43.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 43, we get 43.
Bring next digit (5) of the dividend behind the 43 and repeat the process: 435 / 561

Advancing to step 3:
561 goes into 435 0 times with a remainder of 435.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 435, we end up with 435.
Bring next digit (9) of the dividend behind the 435 and repeat the process: 4359 / 561

Let's proceed to step 4:
561 can be fit into 4359 7 times, resulting in a remainder of 432.
Put 7 as the next digit of the answer. 
Result so far: 7.0
If we take 3927 away from 4359, we end up with 432.
Grab the next digit (9) from the dividend, add it to 432, then carry on: 4329 / 561

Advancing to step 5:
561 goes into 4329 7 times with a remainder of 402.
The number 7 becomes the next digit in our result. 
Result so far: 77.0
The remainder is 402 after subtracting 3927 from 4329.
Append the next digit (3) from the dividend to 402 and continue with: 4023 / 561

Let's proceed to step 6:
When dividing 4023 by 561, we get 7 with a remainder of 96.
Use 7 as the next digit of our solution. 
Result so far: 777.0
Subtract 3927 from 4023 to get 96.
Take the next digit (6) from the dividend and append it to 96, then repeat: 966 / 561

On to step 7:
561 goes into 966 1 times with a remainder of 405.
Put 1 as the next digit of the answer. 
Result so far: 7771.0
If we subtract 561 from 966, we get 405.
Take the next digit (5) from the dividend and append it to 405, then repeat: 4055 / 561

Let's proceed to step 8:
561 goes into 4055 7 times with a remainder of 128.
The number 7 becomes the next digit in our result. 
Result so far: 77717.0
Subtracting 3927 from 4055 leaves us with 128.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1280, and continue the process.

Advancing to step 9:
If we divide 1280 by 561, we get 2 and a remainder of 158.
Use 2 as the next digit of our solution. 
Result so far: 77717.2
If we take 1122 away from 1280, we end up with 158.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1580, and continue the process.

Step 10:
1580 divided by 561 is 2 with a remainder of 458.
Write down 2 as next digit of the result. 
Result so far: 77717.22
If we subtract 1122 from 1580, we get 458.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4580, and continue the process.

The quotient of the division is 77717.22, and the remainder is 0.458.