87990721 ÷ 249 
The aim is to understand the frequency of 249 in 87990721.

Moving on to step 1:
When dividing 8 by 249, we get 0 with a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Take the next digit (7) from the dividend and append it to 8, then repeat: 87 / 249

Advancing to step 2:
The number 249 fits into 87 0 times, leaving a remainder of 87.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 87 to get 87.
Grab the next digit (9) from the dividend, add it to 87, then carry on: 879 / 249

Advancing to step 3:
249 can be fit into 879 3 times, resulting in a remainder of 132.
Use 3 as the next digit of our solution. 
Result so far: 3.0
If we subtract 747 from 879, we get 132.
Fetch the next digit (9) from the dividend, attach it to 132 and continue: 1329 / 249

Moving on to step 4:
1329 divided by 249 is 5 with a remainder of 84.
Use 5 as the next digit of our solution. 
Result so far: 35.0
The remainder is 84 after subtracting 1245 from 1329.
Bring next digit (0) of the dividend behind the 84 and repeat the process: 840 / 249

Advancing to step 5:
249 goes into 840 3 times with a remainder of 93.
Put 3 as the next digit of the answer. 
Result so far: 353.0
The remainder is 93 after subtracting 747 from 840.
Include the next digit (7) from the dividend after 93, then repeat: 937 / 249

On to step 6:
249 goes into 937 3 times with a remainder of 190.
The number 3 becomes the next digit in our result. 
Result so far: 3533.0
Subtracting 747 from 937 leaves us with 190.
Fetch the next digit (2) from the dividend, attach it to 190 and continue: 1902 / 249

Let's proceed to step 7:
1902 divided by 249 is 7 with a remainder of 159.
The number 7 becomes the next digit in our result. 
Result so far: 35337.0
Subtracting 1743 from 1902 leaves us with 159.
Grab the next digit (1) from the dividend, add it to 159, then carry on: 1591 / 249

Advancing to step 8:
If we divide 1591 by 249, we get 6 and a remainder of 97.
Use 6 as the next digit of our solution. 
Result so far: 353376.0
Deduct 1494 from 1591 and we're left with 97.
Since there are no more digits in the dividend, we add a zero to the remainder making it 970, and continue the process.

Advancing to step 9:
If we divide 970 by 249, we get 3 and a remainder of 223.
Use 3 as the next digit of our solution. 
Result so far: 353376.3
If we take 747 away from 970, we end up with 223.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2230, and continue the process.

On to step 10:
The number 249 fits into 2230 8 times, leaving a remainder of 238.
Use 8 as the next digit of our solution. 
Result so far: 353376.38
The remainder is 238 after subtracting 1992 from 2230.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2380, and continue the process.

Step 11:
249 can be fit into 2380 9 times, resulting in a remainder of 139.
The number 9 becomes the next digit in our result. 
Result so far: 353376.389
The remainder is 139 after subtracting 2241 from 2380.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1390, and continue the process.

On to step 12:
249 can be fit into 1390 5 times, resulting in a remainder of 145.
Record the quotient 5 as the next digit in the result. 
Result so far: 353376.3895
Subtract 1245 from 1390 to get 145.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1450, and continue the process.

On to step 13:
The number 249 fits into 1450 5 times, leaving a remainder of 205.
Write down 5 as next digit of the result. 
Result so far: 353376.38955
The remainder is 205 after subtracting 1245 from 1450.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2050, and continue the process.

After the division, we end up with 353376.38955 and a remainder of 0.000205.