We look at the division of 64343292 by 420 
The aim is to understand the frequency of 420 in 64343292.

Going ahead to step 1:
The number 420 fits into 6 0 times, leaving a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Append the next digit (4) from the dividend to 6 and continue with: 64 / 420

Advancing to step 2:
If we divide 64 by 420, we get 0 and a remainder of 64.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 64 leaves us with 64.
Grab the next digit (3) from the dividend, add it to 64, then carry on: 643 / 420

Advancing to step 3:
When dividing 643 by 420, we get 1 with a remainder of 223.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we subtract 420 from 643, we get 223.
Append the next digit (4) from the dividend to 223 and continue with: 2234 / 420

Step 4:
420 can be fit into 2234 5 times, resulting in a remainder of 134.
Use 5 as the next digit of our solution. 
Result so far: 15.0
If we take 2100 away from 2234, we end up with 134.
Bring next digit (3) of the dividend behind the 134 and repeat the process: 1343 / 420

On to step 5:
When dividing 1343 by 420, we get 3 with a remainder of 83.
The next digit of our result is 3. 
Result so far: 153.0
Deduct 1260 from 1343 and we're left with 83.
Bring next digit (2) of the dividend behind the 83 and repeat the process: 832 / 420

Let's proceed to step 6:
832 divided by 420 is 1 with a remainder of 412.
Use 1 as the next digit of our solution. 
Result so far: 1531.0
Subtract 420 from 832 to get 412.
Grab the next digit (9) from the dividend, add it to 412, then carry on: 4129 / 420

Let's proceed to step 7:
420 goes into 4129 9 times with a remainder of 349.
The next digit of our result is 9. 
Result so far: 15319.0
Subtracting 3780 from 4129 leaves us with 349.
Include the next digit (2) from the dividend after 349, then repeat: 3492 / 420

Advancing to step 8:
3492 divided by 420 is 8 with a remainder of 132.
The number 8 becomes the next digit in our result. 
Result so far: 153198.0
If we take 3360 away from 3492, we end up with 132.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1320, and continue the process.

Advancing to step 9:
1320 divided by 420 is 3 with a remainder of 60.
Use 3 as the next digit of our solution. 
Result so far: 153198.3
Deduct 1260 from 1320 and we're left with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Moving on to step 10:
420 can be fit into 600 1 times, resulting in a remainder of 180.
The number 1 becomes the next digit in our result. 
Result so far: 153198.31
If we take 420 away from 600, we end up with 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1800, and continue the process.

Let's proceed to step 11:
When dividing 1800 by 420, we get 4 with a remainder of 120.
Use 4 as the next digit of our solution. 
Result so far: 153198.314
Deduct 1680 from 1800 and we're left with 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Moving on to step 12:
When dividing 1200 by 420, we get 2 with a remainder of 360.
Put 2 as the next digit of the answer. 
Result so far: 153198.3142
The remainder is 360 after subtracting 840 from 1200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Let's proceed to step 13:
If we divide 3600 by 420, we get 8 and a remainder of 240.
The next digit of our result is 8. 
Result so far: 153198.31428
Subtracting 3360 from 3600 leaves us with 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2400, and continue the process.

Step 14:
If we divide 2400 by 420, we get 5 and a remainder of 300.
The next digit of our result is 5. 
Result so far: 153198.314285
If we take 2100 away from 2400, we end up with 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3000, and continue the process.

Advancing to step 15:
3000 divided by 420 is 7 with a remainder of 60.
Record the quotient 7 as the next digit in the result. 
Result so far: 153198.3142857
Subtracting 2940 from 3000 leaves us with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Going ahead to step 16:
The number 420 fits into 600 1 times, leaving a remainder of 180.
Put 1 as the next digit of the answer. 
Result so far: 153198.31428571
If we subtract 420 from 600, we get 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1800, and continue the process.

The final outcome is 153198.31428571, with a leftover of 1.8e-07.