We're dividing 429880 by 42 
The aim is to understand the frequency of 42 in 429880.

On to step 1:
42 can be fit into 4 0 times, resulting in a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Grab the next digit (2) from the dividend, add it to 4, then carry on: 42 / 42

Going ahead to step 2:
42 goes into 42 1 times with a remainder of 0.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 42 from 42 leaves us with 0.
Grab the next digit (9) from the dividend, add it to 0, then carry on: 9 / 42

On to step 3:
9 divided by 42 is 0 with a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
Deduct 0 from 9 and we're left with 9.
Bring next digit (8) of the dividend behind the 9 and repeat the process: 98 / 42

Advancing to step 4:
42 goes into 98 2 times with a remainder of 14.
Put 2 as the next digit of the answer. 
Result so far: 102.0
Subtract 84 from 98 to get 14.
Take the next digit (8) from the dividend and append it to 14, then repeat: 148 / 42

Going ahead to step 5:
42 goes into 148 3 times with a remainder of 22.
The next digit of our result is 3. 
Result so far: 1023.0
Subtracting 126 from 148 leaves us with 22.
Append the next digit (0) from the dividend to 22 and continue with: 220 / 42

Let's proceed to step 6:
220 divided by 42 is 5 with a remainder of 10.
Use 5 as the next digit of our solution. 
Result so far: 10235.0
Deduct 210 from 220 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 7:
The number 42 fits into 100 2 times, leaving a remainder of 16.
The number 2 becomes the next digit in our result. 
Result so far: 10235.2
If we subtract 84 from 100, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 8:
42 can be fit into 160 3 times, resulting in a remainder of 34.
The next digit of our result is 3. 
Result so far: 10235.23
If we subtract 126 from 160, we get 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

On to step 9:
The number 42 fits into 340 8 times, leaving a remainder of 4.
Write down 8 as next digit of the result. 
Result so far: 10235.238
The remainder is 4 after subtracting 336 from 340.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 10:
The number 42 fits into 40 0 times, leaving a remainder of 40.
The next digit of our result is 0. 
Result so far: 10235.238
If we take 0 away from 40, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 11:
When dividing 400 by 42, we get 9 with a remainder of 22.
Use 9 as the next digit of our solution. 
Result so far: 10235.23809
Subtracting 378 from 400 leaves us with 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

Advancing to step 12:
The number 42 fits into 220 5 times, leaving a remainder of 10.
Write down 5 as next digit of the result. 
Result so far: 10235.238095
Deduct 210 from 220 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 13:
42 can be fit into 100 2 times, resulting in a remainder of 16.
Use 2 as the next digit of our solution. 
Result so far: 10235.2380952
If we subtract 84 from 100, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 14:
42 can be fit into 160 3 times, resulting in a remainder of 34.
Record the quotient 3 as the next digit in the result. 
Result so far: 10235.23809523
The remainder is 34 after subtracting 126 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

The final result is 10235.23809523 with a remainder of 3.4e-08.