99657388 ÷ 401 
The aim is to understand the frequency of 401 in 99657388.

Advancing to step 1:
When dividing 9 by 401, we get 0 with a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Bring next digit (9) of the dividend behind the 9 and repeat the process: 99 / 401

On to step 2:
The number 401 fits into 99 0 times, leaving a remainder of 99.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 99, we get 99.
Include the next digit (6) from the dividend after 99, then repeat: 996 / 401

Going ahead to step 3:
401 goes into 996 2 times with a remainder of 194.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
Subtracting 802 from 996 leaves us with 194.
Take the next digit (5) from the dividend and append it to 194, then repeat: 1945 / 401

Moving on to step 4:
If we divide 1945 by 401, we get 4 and a remainder of 341.
The next digit of our result is 4. 
Result so far: 24.0
Deduct 1604 from 1945 and we're left with 341.
Take the next digit (7) from the dividend and append it to 341, then repeat: 3417 / 401

Let's proceed to step 5:
401 goes into 3417 8 times with a remainder of 209.
The next digit of our result is 8. 
Result so far: 248.0
Subtracting 3208 from 3417 leaves us with 209.
Fetch the next digit (3) from the dividend, attach it to 209 and continue: 2093 / 401

Step 6:
401 goes into 2093 5 times with a remainder of 88.
Put 5 as the next digit of the answer. 
Result so far: 2485.0
If we take 2005 away from 2093, we end up with 88.
Take the next digit (8) from the dividend and append it to 88, then repeat: 888 / 401

Step 7:
401 can be fit into 888 2 times, resulting in a remainder of 86.
Write down 2 as next digit of the result. 
Result so far: 24852.0
The remainder is 86 after subtracting 802 from 888.
Append the next digit (8) from the dividend to 86 and continue with: 868 / 401

Let's proceed to step 8:
When dividing 868 by 401, we get 2 with a remainder of 66.
Write down 2 as next digit of the result. 
Result so far: 248522.0
If we take 802 away from 868, we end up with 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Advancing to step 9:
If we divide 660 by 401, we get 1 and a remainder of 259.
Use 1 as the next digit of our solution. 
Result so far: 248522.1
The remainder is 259 after subtracting 401 from 660.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2590, and continue the process.

Going ahead to step 10:
The number 401 fits into 2590 6 times, leaving a remainder of 184.
The number 6 becomes the next digit in our result. 
Result so far: 248522.16
The remainder is 184 after subtracting 2406 from 2590.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1840, and continue the process.

Advancing to step 11:
401 goes into 1840 4 times with a remainder of 236.
Record the quotient 4 as the next digit in the result. 
Result so far: 248522.164
If we subtract 1604 from 1840, we get 236.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2360, and continue the process.

Let's proceed to step 12:
401 goes into 2360 5 times with a remainder of 355.
The number 5 becomes the next digit in our result. 
Result so far: 248522.1645
Subtract 2005 from 2360 to get 355.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3550, and continue the process.

Step 13:
3550 divided by 401 is 8 with a remainder of 342.
Use 8 as the next digit of our solution. 
Result so far: 248522.16458
Deduct 3208 from 3550 and we're left with 342.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3420, and continue the process.

Moving on to step 14:
401 goes into 3420 8 times with a remainder of 212.
Record the quotient 8 as the next digit in the result. 
Result so far: 248522.164588
Deduct 3208 from 3420 and we're left with 212.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2120, and continue the process.

Our division results in 248522.164588 with a remaining 2.12e-05.