We look at the division of 61740304 by 621 
The aim is to understand the frequency of 621 in 61740304.

On to step 1:
If we divide 6 by 621, we get 0 and a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Include the next digit (1) from the dividend after 6, then repeat: 61 / 621

Going ahead to step 2:
When dividing 61 by 621, we get 0 with a remainder of 61.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 61, we end up with 61.
Bring next digit (7) of the dividend behind the 61 and repeat the process: 617 / 621

Step 3:
If we divide 617 by 621, we get 0 and a remainder of 617.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 617, we end up with 617.
Bring next digit (4) of the dividend behind the 617 and repeat the process: 6174 / 621

Let's proceed to step 4:
6174 divided by 621 is 9 with a remainder of 585.
Use 9 as the next digit of our solution. 
Result so far: 9.0
Subtracting 5589 from 6174 leaves us with 585.
Take the next digit (0) from the dividend and append it to 585, then repeat: 5850 / 621

Moving on to step 5:
5850 divided by 621 is 9 with a remainder of 261.
Use 9 as the next digit of our solution. 
Result so far: 99.0
If we take 5589 away from 5850, we end up with 261.
Include the next digit (3) from the dividend after 261, then repeat: 2613 / 621

Let's proceed to step 6:
If we divide 2613 by 621, we get 4 and a remainder of 129.
Put 4 as the next digit of the answer. 
Result so far: 994.0
Deduct 2484 from 2613 and we're left with 129.
Take the next digit (0) from the dividend and append it to 129, then repeat: 1290 / 621

Let's proceed to step 7:
621 can be fit into 1290 2 times, resulting in a remainder of 48.
Write down 2 as next digit of the result. 
Result so far: 9942.0
Subtracting 1242 from 1290 leaves us with 48.
Grab the next digit (4) from the dividend, add it to 48, then carry on: 484 / 621

Let's proceed to step 8:
When dividing 484 by 621, we get 0 with a remainder of 484.
Record the quotient 0 as the next digit in the result. 
Result so far: 99420.0
The remainder is 484 after subtracting 0 from 484.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4840, and continue the process.

Moving on to step 9:
When dividing 4840 by 621, we get 7 with a remainder of 493.
Use 7 as the next digit of our solution. 
Result so far: 99420.7
Deduct 4347 from 4840 and we're left with 493.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4930, and continue the process.

Let's proceed to step 10:
621 goes into 4930 7 times with a remainder of 583.
Record the quotient 7 as the next digit in the result. 
Result so far: 99420.77
If we subtract 4347 from 4930, we get 583.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5830, and continue the process.

After the division, we end up with 99420.77 and a remainder of 0.583.