10021549 divided by 780 
The aim is to understand the frequency of 780 in 10021549.

Going ahead to step 1:
780 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
If we subtract 0 from 1, we get 1.
Append the next digit (0) from the dividend to 1 and continue with: 10 / 780

On to step 2:
The number 780 fits into 10 0 times, leaving a remainder of 10.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 10 after subtracting 0 from 10.
Append the next digit (0) from the dividend to 10 and continue with: 100 / 780

Going ahead to step 3:
780 can be fit into 100 0 times, resulting in a remainder of 100.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 100 to get 100.
Grab the next digit (2) from the dividend, add it to 100, then carry on: 1002 / 780

Advancing to step 4:
When dividing 1002 by 780, we get 1 with a remainder of 222.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtract 780 from 1002 to get 222.
Append the next digit (1) from the dividend to 222 and continue with: 2221 / 780

Going ahead to step 5:
If we divide 2221 by 780, we get 2 and a remainder of 661.
Record the quotient 2 as the next digit in the result. 
Result so far: 12.0
The remainder is 661 after subtracting 1560 from 2221.
Append the next digit (5) from the dividend to 661 and continue with: 6615 / 780

Going ahead to step 6:
If we divide 6615 by 780, we get 8 and a remainder of 375.
Record the quotient 8 as the next digit in the result. 
Result so far: 128.0
Subtract 6240 from 6615 to get 375.
Include the next digit (4) from the dividend after 375, then repeat: 3754 / 780

Moving on to step 7:
780 goes into 3754 4 times with a remainder of 634.
Use 4 as the next digit of our solution. 
Result so far: 1284.0
If we subtract 3120 from 3754, we get 634.
Bring next digit (9) of the dividend behind the 634 and repeat the process: 6349 / 780

Step 8:
780 can be fit into 6349 8 times, resulting in a remainder of 109.
The next digit of our result is 8. 
Result so far: 12848.0
If we take 6240 away from 6349, we end up with 109.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1090, and continue the process.

Let's proceed to step 9:
780 can be fit into 1090 1 times, resulting in a remainder of 310.
Use 1 as the next digit of our solution. 
Result so far: 12848.1
The remainder is 310 after subtracting 780 from 1090.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3100, and continue the process.

Step 10:
If we divide 3100 by 780, we get 3 and a remainder of 760.
The number 3 becomes the next digit in our result. 
Result so far: 12848.13
Subtract 2340 from 3100 to get 760.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7600, and continue the process.

Step 11:
When dividing 7600 by 780, we get 9 with a remainder of 580.
Record the quotient 9 as the next digit in the result. 
Result so far: 12848.139
If we take 7020 away from 7600, we end up with 580.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5800, and continue the process.

On to step 12:
When dividing 5800 by 780, we get 7 with a remainder of 340.
The next digit of our result is 7. 
Result so far: 12848.1397
Deduct 5460 from 5800 and we're left with 340.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3400, and continue the process.

Step 13:
The number 780 fits into 3400 4 times, leaving a remainder of 280.
The number 4 becomes the next digit in our result. 
Result so far: 12848.13974
If we take 3120 away from 3400, we end up with 280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2800, and continue the process.

Advancing to step 14:
If we divide 2800 by 780, we get 3 and a remainder of 460.
Record the quotient 3 as the next digit in the result. 
Result so far: 12848.139743
The remainder is 460 after subtracting 2340 from 2800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4600, and continue the process.

Let's proceed to step 15:
The number 780 fits into 4600 5 times, leaving a remainder of 700.
Write down 5 as next digit of the result. 
Result so far: 12848.1397435
If we subtract 3900 from 4600, we get 700.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7000, and continue the process.

On to step 16:
If we divide 7000 by 780, we get 8 and a remainder of 760.
Use 8 as the next digit of our solution. 
Result so far: 12848.13974358
Subtract 6240 from 7000 to get 760.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7600, and continue the process.

After the division, we end up with 12848.13974358 and a remainder of 7.6e-07.