7022405 ÷ 420 
The aim is to understand the frequency of 420 in 7022405.

Advancing to step 1:
7 divided by 420 is 0 with a remainder of 7.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 7 and we're left with 7.
Grab the next digit (0) from the dividend, add it to 7, then carry on: 70 / 420

Moving on to step 2:
70 divided by 420 is 0 with a remainder of 70.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 70, we get 70.
Include the next digit (2) from the dividend after 70, then repeat: 702 / 420

On to step 3:
702 divided by 420 is 1 with a remainder of 282.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we subtract 420 from 702, we get 282.
Fetch the next digit (2) from the dividend, attach it to 282 and continue: 2822 / 420

Advancing to step 4:
420 goes into 2822 6 times with a remainder of 302.
Put 6 as the next digit of the answer. 
Result so far: 16.0
Subtract 2520 from 2822 to get 302.
Fetch the next digit (4) from the dividend, attach it to 302 and continue: 3024 / 420

Advancing to step 5:
420 can be fit into 3024 7 times, resulting in a remainder of 84.
The next digit of our result is 7. 
Result so far: 167.0
The remainder is 84 after subtracting 2940 from 3024.
Include the next digit (0) from the dividend after 84, then repeat: 840 / 420

On to step 6:
If we divide 840 by 420, we get 2 and a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 1672.0
If we subtract 840 from 840, we get 0.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 420

Step 7:
If we divide 5 by 420, we get 0 and a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 16720.0
Subtracting 0 from 5 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 8:
50 divided by 420 is 0 with a remainder of 50.
Record the quotient 0 as the next digit in the result. 
Result so far: 16720.0
Deduct 0 from 50 and we're left with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Let's proceed to step 9:
The number 420 fits into 500 1 times, leaving a remainder of 80.
The number 1 becomes the next digit in our result. 
Result so far: 16720.01
Deduct 420 from 500 and we're left with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Let's proceed to step 10:
When dividing 800 by 420, we get 1 with a remainder of 380.
Use 1 as the next digit of our solution. 
Result so far: 16720.011
If we subtract 420 from 800, we get 380.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3800, and continue the process.

Our division results in 16720.011 with a remaining 0.038.