We look at the division of 64416904 by 161 
The aim is to understand the frequency of 161 in 64416904.

Moving on to step 1:
If we divide 6 by 161, we get 0 and a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 161

Moving on to step 2:
161 goes into 64 0 times with a remainder of 64.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 64 and we're left with 64.
Fetch the next digit (4) from the dividend, attach it to 64 and continue: 644 / 161

Going ahead to step 3:
161 can be fit into 644 4 times, resulting in a remainder of 0.
Record the quotient 4 as the next digit in the result. 
Result so far: 4.0
If we take 644 away from 644, we end up with 0.
Fetch the next digit (1) from the dividend, attach it to 0 and continue: 1 / 161

On to step 4:
The number 161 fits into 1 0 times, leaving a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 40.0
If we subtract 0 from 1, we get 1.
Bring next digit (6) of the dividend behind the 1 and repeat the process: 16 / 161

Moving on to step 5:
16 divided by 161 is 0 with a remainder of 16.
The number 0 becomes the next digit in our result. 
Result so far: 400.0
Subtracting 0 from 16 leaves us with 16.
Append the next digit (9) from the dividend to 16 and continue with: 169 / 161

On to step 6:
The number 161 fits into 169 1 times, leaving a remainder of 8.
Use 1 as the next digit of our solution. 
Result so far: 4001.0
Subtract 161 from 169 to get 8.
Take the next digit (0) from the dividend and append it to 8, then repeat: 80 / 161

Moving on to step 7:
The number 161 fits into 80 0 times, leaving a remainder of 80.
The next digit of our result is 0. 
Result so far: 40010.0
The remainder is 80 after subtracting 0 from 80.
Grab the next digit (4) from the dividend, add it to 80, then carry on: 804 / 161

Going ahead to step 8:
If we divide 804 by 161, we get 4 and a remainder of 160.
The next digit of our result is 4. 
Result so far: 400104.0
If we subtract 644 from 804, we get 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1600, and continue the process.

Advancing to step 9:
If we divide 1600 by 161, we get 9 and a remainder of 151.
The number 9 becomes the next digit in our result. 
Result so far: 400104.9
If we take 1449 away from 1600, we end up with 151.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1510, and continue the process.

Moving on to step 10:
When dividing 1510 by 161, we get 9 with a remainder of 61.
The number 9 becomes the next digit in our result. 
Result so far: 400104.99
If we subtract 1449 from 1510, we get 61.
Since there are no more digits in the dividend, we add a zero to the remainder making it 610, and continue the process.

The final result is 400104.99 with a remainder of 0.061.