We look at the division of 19581578 by 501 
The aim is to understand the frequency of 501 in 19581578.

Going ahead to step 1:
501 goes into 1 0 times with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Append the next digit (9) from the dividend to 1 and continue with: 19 / 501

Moving on to step 2:
19 divided by 501 is 0 with a remainder of 19.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 19, we end up with 19.
Take the next digit (5) from the dividend and append it to 19, then repeat: 195 / 501

On to step 3:
If we divide 195 by 501, we get 0 and a remainder of 195.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 195 and we're left with 195.
Take the next digit (8) from the dividend and append it to 195, then repeat: 1958 / 501

Going ahead to step 4:
501 goes into 1958 3 times with a remainder of 455.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Subtract 1503 from 1958 to get 455.
Take the next digit (1) from the dividend and append it to 455, then repeat: 4551 / 501

Step 5:
4551 divided by 501 is 9 with a remainder of 42.
Write down 9 as next digit of the result. 
Result so far: 39.0
The remainder is 42 after subtracting 4509 from 4551.
Bring next digit (5) of the dividend behind the 42 and repeat the process: 425 / 501

Advancing to step 6:
501 goes into 425 0 times with a remainder of 425.
Put 0 as the next digit of the answer. 
Result so far: 390.0
Subtract 0 from 425 to get 425.
Take the next digit (7) from the dividend and append it to 425, then repeat: 4257 / 501

Moving on to step 7:
The number 501 fits into 4257 8 times, leaving a remainder of 249.
The next digit of our result is 8. 
Result so far: 3908.0
Deduct 4008 from 4257 and we're left with 249.
Grab the next digit (8) from the dividend, add it to 249, then carry on: 2498 / 501

Let's proceed to step 8:
501 goes into 2498 4 times with a remainder of 494.
The number 4 becomes the next digit in our result. 
Result so far: 39084.0
If we take 2004 away from 2498, we end up with 494.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4940, and continue the process.

On to step 9:
If we divide 4940 by 501, we get 9 and a remainder of 431.
Put 9 as the next digit of the answer. 
Result so far: 39084.9
The remainder is 431 after subtracting 4509 from 4940.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4310, and continue the process.

Advancing to step 10:
When dividing 4310 by 501, we get 8 with a remainder of 302.
The next digit of our result is 8. 
Result so far: 39084.98
Subtract 4008 from 4310 to get 302.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3020, and continue the process.

Step 11:
If we divide 3020 by 501, we get 6 and a remainder of 14.
Use 6 as the next digit of our solution. 
Result so far: 39084.986
If we subtract 3006 from 3020, we get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Let's proceed to step 12:
501 goes into 140 0 times with a remainder of 140.
Put 0 as the next digit of the answer. 
Result so far: 39084.986
If we subtract 0 from 140, we get 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

Step 13:
The number 501 fits into 1400 2 times, leaving a remainder of 398.
Put 2 as the next digit of the answer. 
Result so far: 39084.98602
If we take 1002 away from 1400, we end up with 398.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3980, and continue the process.

Step 14:
501 can be fit into 3980 7 times, resulting in a remainder of 473.
Use 7 as the next digit of our solution. 
Result so far: 39084.986027
If we take 3507 away from 3980, we end up with 473.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4730, and continue the process.

On to step 15:
The number 501 fits into 4730 9 times, leaving a remainder of 221.
Write down 9 as next digit of the result. 
Result so far: 39084.9860279
If we take 4509 away from 4730, we end up with 221.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2210, and continue the process.

Let's proceed to step 16:
When dividing 2210 by 501, we get 4 with a remainder of 206.
Record the quotient 4 as the next digit in the result. 
Result so far: 39084.98602794
Deduct 2004 from 2210 and we're left with 206.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2060, and continue the process.

The quotient of the division is 39084.98602794, and the remainder is 2.06e-07.