We look at the division of 371609 by 20 
The aim is to understand the frequency of 20 in 371609.

Let's proceed to step 1:
The number 20 fits into 3 0 times, leaving a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Grab the next digit (7) from the dividend, add it to 3, then carry on: 37 / 20

Let's proceed to step 2:
20 can be fit into 37 1 times, resulting in a remainder of 17.
The next digit of our result is 1. 
Result so far: 1.0
The remainder is 17 after subtracting 20 from 37.
Include the next digit (1) from the dividend after 17, then repeat: 171 / 20

Going ahead to step 3:
20 can be fit into 171 8 times, resulting in a remainder of 11.
Put 8 as the next digit of the answer. 
Result so far: 18.0
The remainder is 11 after subtracting 160 from 171.
Grab the next digit (6) from the dividend, add it to 11, then carry on: 116 / 20

Going ahead to step 4:
116 divided by 20 is 5 with a remainder of 16.
Use 5 as the next digit of our solution. 
Result so far: 185.0
The remainder is 16 after subtracting 100 from 116.
Append the next digit (0) from the dividend to 16 and continue with: 160 / 20

On to step 5:
160 divided by 20 is 8 with a remainder of 0.
The number 8 becomes the next digit in our result. 
Result so far: 1858.0
Subtracting 160 from 160 leaves us with 0.
Append the next digit (9) from the dividend to 0 and continue with: 9 / 20

Step 6:
9 divided by 20 is 0 with a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 18580.0
Subtracting 0 from 9 leaves us with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 7:
The number 20 fits into 90 4 times, leaving a remainder of 10.
Record the quotient 4 as the next digit in the result. 
Result so far: 18580.4
Subtracting 80 from 90 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 8:
The number 20 fits into 100 5 times, leaving a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 18580.45
The remainder is 0 after subtracting 100 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 9:
When dividing 0 by 20, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 18580.45
If we take 0 away from 0, 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.

Advancing to step 10:
20 can be fit into 0 0 times, resulting in a remainder of 0.
The next digit of our result is 0. 
Result so far: 18580.45
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 18580.45, with a leftover of 0.0.