Let's divide 421553 by 12
The aim is to understand the frequency of 12 in 421553.

Let's proceed to step 1:
When dividing 4 by 12, we get 0 with a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Take the next digit (2) from the dividend and append it to 4, then repeat: 42 / 12

Step 2:
When dividing 42 by 12, we get 3 with a remainder of 6.
Write down 3 as next digit of the result. 
Result so far: 3.0
The remainder is 6 after subtracting 36 from 42.
Fetch the next digit (1) from the dividend, attach it to 6 and continue: 61 / 12

Let's proceed to step 3:
If we divide 61 by 12, we get 5 and a remainder of 1.
Put 5 as the next digit of the answer. 
Result so far: 35.0
If we take 60 away from 61, we end up with 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 12

Moving on to step 4:
15 divided by 12 is 1 with a remainder of 3.
The next digit of our result is 1. 
Result so far: 351.0
Deduct 12 from 15 and we're left with 3.
Fetch the next digit (5) from the dividend, attach it to 3 and continue: 35 / 12

Moving on to step 5:
12 can be fit into 35 2 times, resulting in a remainder of 11.
The next digit of our result is 2. 
Result so far: 3512.0
The remainder is 11 after subtracting 24 from 35.
Take the next digit (3) from the dividend and append it to 11, then repeat: 113 / 12

On to step 6:
The number 12 fits into 113 9 times, leaving a remainder of 5.
Use 9 as the next digit of our solution. 
Result so far: 35129.0
Subtract 108 from 113 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 7:
12 goes into 50 4 times with a remainder of 2.
The next digit of our result is 4. 
Result so far: 35129.4
Subtract 48 from 50 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 8:
When dividing 20 by 12, we get 1 with a remainder of 8.
Use 1 as the next digit of our solution. 
Result so far: 35129.41
The remainder is 8 after subtracting 12 from 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 9:
The number 12 fits into 80 6 times, leaving a remainder of 8.
Use 6 as the next digit of our solution. 
Result so far: 35129.416
If we take 72 away from 80, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 10:
12 goes into 80 6 times with a remainder of 8.
Put 6 as the next digit of the answer. 
Result so far: 35129.4166
The remainder is 8 after subtracting 72 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Our division results in 35129.4166 with a remaining 8e-05.