420852 ÷ 15 
The aim is to understand the frequency of 15 in 420852.

Advancing to step 1:
The number 15 fits into 4 0 times, leaving a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 15

Going ahead to step 2:
15 can be fit into 42 2 times, resulting in a remainder of 12.
Use 2 as the next digit of our solution. 
Result so far: 2.0
The remainder is 12 after subtracting 30 from 42.
Fetch the next digit (0) from the dividend, attach it to 12 and continue: 120 / 15

On to step 3:
When dividing 120 by 15, we get 8 with a remainder of 0.
Put 8 as the next digit of the answer. 
Result so far: 28.0
Deduct 120 from 120 and we're left with 0.
Fetch the next digit (8) from the dividend, attach it to 0 and continue: 8 / 15

Moving on to step 4:
When dividing 8 by 15, we get 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 280.0
Subtracting 0 from 8 leaves us with 8.
Include the next digit (5) from the dividend after 8, then repeat: 85 / 15

Advancing to step 5:
The number 15 fits into 85 5 times, leaving a remainder of 10.
The number 5 becomes the next digit in our result. 
Result so far: 2805.0
If we take 75 away from 85, we end up with 10.
Append the next digit (2) from the dividend to 10 and continue with: 102 / 15

On to step 6:
The number 15 fits into 102 6 times, leaving a remainder of 12.
Put 6 as the next digit of the answer. 
Result so far: 28056.0
Subtracting 90 from 102 leaves us 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.

Going ahead to step 7:
15 goes into 120 8 times with a remainder of 0.
Use 8 as the next digit of our solution. 
Result so far: 28056.8
If we take 120 away from 120, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 8:
When dividing 0 by 15, we get 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 28056.8
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 9:
15 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 28056.8
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 28056.8 with a remaining 0.0.