We look at the division of 90784449 by 646 
The aim is to understand the frequency of 646 in 90784449.

Advancing to step 1:
9 divided by 646 is 0 with a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 9 and we're left with 9.
Append the next digit (0) from the dividend to 9 and continue with: 90 / 646

Moving on to step 2:
90 divided by 646 is 0 with a remainder of 90.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 90 after subtracting 0 from 90.
Include the next digit (7) from the dividend after 90, then repeat: 907 / 646

Advancing to step 3:
907 divided by 646 is 1 with a remainder of 261.
The next digit of our result is 1. 
Result so far: 1.0
If we subtract 646 from 907, we get 261.
Append the next digit (8) from the dividend to 261 and continue with: 2618 / 646

Moving on to step 4:
If we divide 2618 by 646, we get 4 and a remainder of 34.
Put 4 as the next digit of the answer. 
Result so far: 14.0
Subtracting 2584 from 2618 leaves us with 34.
Append the next digit (4) from the dividend to 34 and continue with: 344 / 646

Let's proceed to step 5:
If we divide 344 by 646, we get 0 and a remainder of 344.
Write down 0 as next digit of the result. 
Result so far: 140.0
Deduct 0 from 344 and we're left with 344.
Grab the next digit (4) from the dividend, add it to 344, then carry on: 3444 / 646

Going ahead to step 6:
If we divide 3444 by 646, we get 5 and a remainder of 214.
The next digit of our result is 5. 
Result so far: 1405.0
The remainder is 214 after subtracting 3230 from 3444.
Grab the next digit (4) from the dividend, add it to 214, then carry on: 2144 / 646

Going ahead to step 7:
2144 divided by 646 is 3 with a remainder of 206.
Record the quotient 3 as the next digit in the result. 
Result so far: 14053.0
If we subtract 1938 from 2144, we get 206.
Take the next digit (9) from the dividend and append it to 206, then repeat: 2069 / 646

Let's proceed to step 8:
When dividing 2069 by 646, we get 3 with a remainder of 131.
The number 3 becomes the next digit in our result. 
Result so far: 140533.0
If we take 1938 away from 2069, we end up with 131.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1310, and continue the process.

Moving on to step 9:
646 can be fit into 1310 2 times, resulting in a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 140533.2
Deduct 1292 from 1310 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 10:
646 goes into 180 0 times with a remainder of 180.
Write down 0 as next digit of the result. 
Result so far: 140533.2
If we subtract 0 from 180, we get 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1800, and continue the process.

Moving on to step 11:
646 goes into 1800 2 times with a remainder of 508.
The next digit of our result is 2. 
Result so far: 140533.202
Subtracting 1292 from 1800 leaves us with 508.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5080, and continue the process.

Let's proceed to step 12:
5080 divided by 646 is 7 with a remainder of 558.
Put 7 as the next digit of the answer. 
Result so far: 140533.2027
If we subtract 4522 from 5080, we get 558.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5580, and continue the process.

Step 13:
5580 divided by 646 is 8 with a remainder of 412.
Put 8 as the next digit of the answer. 
Result so far: 140533.20278
If we subtract 5168 from 5580, we get 412.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4120, and continue the process.

Step 14:
4120 divided by 646 is 6 with a remainder of 244.
Record the quotient 6 as the next digit in the result. 
Result so far: 140533.202786
If we subtract 3876 from 4120, we get 244.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2440, and continue the process.

Moving on to step 15:
646 goes into 2440 3 times with a remainder of 502.
Write down 3 as next digit of the result. 
Result so far: 140533.2027863
If we take 1938 away from 2440, we end up with 502.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5020, and continue the process.

Let's proceed to step 16:
646 can be fit into 5020 7 times, resulting in a remainder of 498.
Use 7 as the next digit of our solution. 
Result so far: 140533.20278637
Deduct 4522 from 5020 and we're left with 498.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4980, and continue the process.

Our division results in 140533.20278637 with a remaining 4.98e-07.