Let's divide 21215451 by 486
The aim is to understand the frequency of 486 in 21215451.

On to step 1:
486 can be fit into 2 0 times, resulting in a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 486

Let's proceed to step 2:
When dividing 21 by 486, we get 0 with a remainder of 21.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 21 to get 21.
Grab the next digit (2) from the dividend, add it to 21, then carry on: 212 / 486

Advancing to step 3:
The number 486 fits into 212 0 times, leaving a remainder of 212.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 212 and we're left with 212.
Grab the next digit (1) from the dividend, add it to 212, then carry on: 2121 / 486

Going ahead to step 4:
When dividing 2121 by 486, we get 4 with a remainder of 177.
The next digit of our result is 4. 
Result so far: 4.0
Subtract 1944 from 2121 to get 177.
Bring next digit (5) of the dividend behind the 177 and repeat the process: 1775 / 486

Let's proceed to step 5:
486 can be fit into 1775 3 times, resulting in a remainder of 317.
The next digit of our result is 3. 
Result so far: 43.0
If we take 1458 away from 1775, we end up with 317.
Append the next digit (4) from the dividend to 317 and continue with: 3174 / 486

Going ahead to step 6:
When dividing 3174 by 486, we get 6 with a remainder of 258.
The number 6 becomes the next digit in our result. 
Result so far: 436.0
Subtracting 2916 from 3174 leaves us with 258.
Grab the next digit (5) from the dividend, add it to 258, then carry on: 2585 / 486

Advancing to step 7:
486 can be fit into 2585 5 times, resulting in a remainder of 155.
Put 5 as the next digit of the answer. 
Result so far: 4365.0
The remainder is 155 after subtracting 2430 from 2585.
Include the next digit (1) from the dividend after 155, then repeat: 1551 / 486

Step 8:
The number 486 fits into 1551 3 times, leaving a remainder of 93.
Put 3 as the next digit of the answer. 
Result so far: 43653.0
The remainder is 93 after subtracting 1458 from 1551.
Since there are no more digits in the dividend, we add a zero to the remainder making it 930, and continue the process.

Going ahead to step 9:
The number 486 fits into 930 1 times, leaving a remainder of 444.
Use 1 as the next digit of our solution. 
Result so far: 43653.1
Subtracting 486 from 930 leaves us with 444.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4440, and continue the process.

On to step 10:
When dividing 4440 by 486, we get 9 with a remainder of 66.
The number 9 becomes the next digit in our result. 
Result so far: 43653.19
Subtracting 4374 from 4440 leaves us 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.

Let's proceed to step 11:
If we divide 660 by 486, we get 1 and a remainder of 174.
Put 1 as the next digit of the answer. 
Result so far: 43653.191
Deduct 486 from 660 and we're left with 174.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1740, and continue the process.

Moving on to step 12:
The number 486 fits into 1740 3 times, leaving a remainder of 282.
Write down 3 as next digit of the result. 
Result so far: 43653.1913
Deduct 1458 from 1740 and we're left with 282.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2820, and continue the process.

Moving on to step 13:
When dividing 2820 by 486, we get 5 with a remainder of 390.
Record the quotient 5 as the next digit in the result. 
Result so far: 43653.19135
The remainder is 390 after subtracting 2430 from 2820.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3900, and continue the process.

Going ahead to step 14:
When dividing 3900 by 486, we get 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 43653.191358
Deduct 3888 from 3900 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 15:
486 goes into 120 0 times with a remainder of 120.
Record the quotient 0 as the next digit in the result. 
Result so far: 43653.191358
Subtract 0 from 120 to get 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Advancing to step 16:
486 can be fit into 1200 2 times, resulting in a remainder of 228.
Use 2 as the next digit of our solution. 
Result so far: 43653.19135802
The remainder is 228 after subtracting 972 from 1200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2280, and continue the process.

After the division, we end up with 43653.19135802 and a remainder of 2.28e-07.