We look at the division of 78345471 by 642 
The aim is to understand the frequency of 642 in 78345471.

Advancing to step 1:
When dividing 7 by 642, we get 0 with a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 7 and we're left with 7.
Bring next digit (8) of the dividend behind the 7 and repeat the process: 78 / 642

Advancing to step 2:
When dividing 78 by 642, we get 0 with a remainder of 78.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 78, we end up with 78.
Append the next digit (3) from the dividend to 78 and continue with: 783 / 642

Let's proceed to step 3:
642 goes into 783 1 times with a remainder of 141.
Put 1 as the next digit of the answer. 
Result so far: 1.0
The remainder is 141 after subtracting 642 from 783.
Append the next digit (4) from the dividend to 141 and continue with: 1414 / 642

Going ahead to step 4:
1414 divided by 642 is 2 with a remainder of 130.
The number 2 becomes the next digit in our result. 
Result so far: 12.0
Subtract 1284 from 1414 to get 130.
Append the next digit (5) from the dividend to 130 and continue with: 1305 / 642

Moving on to step 5:
If we divide 1305 by 642, we get 2 and a remainder of 21.
Use 2 as the next digit of our solution. 
Result so far: 122.0
Subtract 1284 from 1305 to get 21.
Bring next digit (4) of the dividend behind the 21 and repeat the process: 214 / 642

Moving on to step 6:
The number 642 fits into 214 0 times, leaving a remainder of 214.
Use 0 as the next digit of our solution. 
Result so far: 1220.0
If we subtract 0 from 214, we get 214.
Grab the next digit (7) from the dividend, add it to 214, then carry on: 2147 / 642

On to step 7:
642 goes into 2147 3 times with a remainder of 221.
Put 3 as the next digit of the answer. 
Result so far: 12203.0
The remainder is 221 after subtracting 1926 from 2147.
Append the next digit (1) from the dividend to 221 and continue with: 2211 / 642

Moving on to step 8:
When dividing 2211 by 642, we get 3 with a remainder of 285.
Write down 3 as next digit of the result. 
Result so far: 122033.0
Subtract 1926 from 2211 to get 285.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2850, and continue the process.

Going ahead to step 9:
2850 divided by 642 is 4 with a remainder of 282.
Write down 4 as next digit of the result. 
Result so far: 122033.4
If we take 2568 away from 2850, we end up with 282.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2820, and continue the process.

On to step 10:
When dividing 2820 by 642, we get 4 with a remainder of 252.
The next digit of our result is 4. 
Result so far: 122033.44
If we subtract 2568 from 2820, we get 252.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2520, and continue the process.

After the division, we end up with 122033.44 and a remainder of 0.252.