60857136 ÷ 420 
The aim is to understand the frequency of 420 in 60857136.

Moving on to step 1:
420 goes into 6 0 times with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Include the next digit (0) from the dividend after 6, then repeat: 60 / 420

Going ahead to step 2:
60 divided by 420 is 0 with a remainder of 60.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 60, we end up with 60.
Take the next digit (8) from the dividend and append it to 60, then repeat: 608 / 420

Going ahead to step 3:
608 divided by 420 is 1 with a remainder of 188.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we take 420 away from 608, we end up with 188.
Include the next digit (5) from the dividend after 188, then repeat: 1885 / 420

On to step 4:
420 goes into 1885 4 times with a remainder of 205.
Use 4 as the next digit of our solution. 
Result so far: 14.0
Deduct 1680 from 1885 and we're left with 205.
Take the next digit (7) from the dividend and append it to 205, then repeat: 2057 / 420

Advancing to step 5:
420 goes into 2057 4 times with a remainder of 377.
Record the quotient 4 as the next digit in the result. 
Result so far: 144.0
If we subtract 1680 from 2057, we get 377.
Take the next digit (1) from the dividend and append it to 377, then repeat: 3771 / 420

Step 6:
420 can be fit into 3771 8 times, resulting in a remainder of 411.
Record the quotient 8 as the next digit in the result. 
Result so far: 1448.0
Subtracting 3360 from 3771 leaves us with 411.
Fetch the next digit (3) from the dividend, attach it to 411 and continue: 4113 / 420

Going ahead to step 7:
420 can be fit into 4113 9 times, resulting in a remainder of 333.
The next digit of our result is 9. 
Result so far: 14489.0
Deduct 3780 from 4113 and we're left with 333.
Bring next digit (6) of the dividend behind the 333 and repeat the process: 3336 / 420

Going ahead to step 8:
420 can be fit into 3336 7 times, resulting in a remainder of 396.
Put 7 as the next digit of the answer. 
Result so far: 144897.0
If we subtract 2940 from 3336, we get 396.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3960, and continue the process.

Moving on to step 9:
The number 420 fits into 3960 9 times, leaving a remainder of 180.
Use 9 as the next digit of our solution. 
Result so far: 144897.9
If we take 3780 away from 3960, 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 10:
1800 divided by 420 is 4 with a remainder of 120.
Use 4 as the next digit of our solution. 
Result so far: 144897.94
If we subtract 1680 from 1800, we 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.

Going ahead to step 11:
420 can be fit into 1200 2 times, resulting in a remainder of 360.
The next digit of our result is 2. 
Result so far: 144897.942
If we take 840 away from 1200, we end up with 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Advancing to step 12:
When dividing 3600 by 420, we get 8 with a remainder of 240.
Write down 8 as next digit of the result. 
Result so far: 144897.9428
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.

Let's proceed to step 13:
The number 420 fits into 2400 5 times, leaving a remainder of 300.
Put 5 as the next digit of the answer. 
Result so far: 144897.94285
Subtract 2100 from 2400 to get 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 14:
420 goes into 3000 7 times with a remainder of 60.
Write down 7 as next digit of the result. 
Result so far: 144897.942857
Subtract 2940 from 3000 to get 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 15:
600 divided by 420 is 1 with a remainder of 180.
The number 1 becomes the next digit in our result. 
Result so far: 144897.9428571
Subtracting 420 from 600 leaves us 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.

On to step 16:
When dividing 1800 by 420, we get 4 with a remainder of 120.
The number 4 becomes the next digit in our result. 
Result so far: 144897.94285714
The remainder is 120 after subtracting 1680 from 1800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

The final outcome is 144897.94285714, with a leftover of 1.2e-07.