7860063 ÷ 378 
The aim is to understand the frequency of 378 in 7860063.

Step 1:
378 can be fit into 7 0 times, resulting in a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 7, we end up with 7.
Take the next digit (8) from the dividend and append it to 7, then repeat: 78 / 378

Advancing to step 2:
78 divided by 378 is 0 with a remainder of 78.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 78 leaves us with 78.
Grab the next digit (6) from the dividend, add it to 78, then carry on: 786 / 378

Moving on to step 3:
The number 378 fits into 786 2 times, leaving a remainder of 30.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtracting 756 from 786 leaves us with 30.
Bring next digit (0) of the dividend behind the 30 and repeat the process: 300 / 378

Going ahead to step 4:
378 can be fit into 300 0 times, resulting in a remainder of 300.
The number 0 becomes the next digit in our result. 
Result so far: 20.0
Subtracting 0 from 300 leaves us with 300.
Take the next digit (0) from the dividend and append it to 300, then repeat: 3000 / 378

On to step 5:
378 can be fit into 3000 7 times, resulting in a remainder of 354.
Record the quotient 7 as the next digit in the result. 
Result so far: 207.0
If we subtract 2646 from 3000, we get 354.
Bring next digit (6) of the dividend behind the 354 and repeat the process: 3546 / 378

Moving on to step 6:
When dividing 3546 by 378, we get 9 with a remainder of 144.
Use 9 as the next digit of our solution. 
Result so far: 2079.0
The remainder is 144 after subtracting 3402 from 3546.
Grab the next digit (3) from the dividend, add it to 144, then carry on: 1443 / 378

Moving on to step 7:
378 goes into 1443 3 times with a remainder of 309.
Put 3 as the next digit of the answer. 
Result so far: 20793.0
Subtracting 1134 from 1443 leaves us with 309.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3090, and continue the process.

Let's proceed to step 8:
If we divide 3090 by 378, we get 8 and a remainder of 66.
The next digit of our result is 8. 
Result so far: 20793.8
The remainder is 66 after subtracting 3024 from 3090.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Going ahead to step 9:
The number 378 fits into 660 1 times, leaving a remainder of 282.
Write down 1 as next digit of the result. 
Result so far: 20793.81
The remainder is 282 after subtracting 378 from 660.
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:
The number 378 fits into 2820 7 times, leaving a remainder of 174.
Record the quotient 7 as the next digit in the result. 
Result so far: 20793.817
Subtracting 2646 from 2820 leaves us with 174.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1740, and continue the process.

Let's proceed to step 11:
378 can be fit into 1740 4 times, resulting in a remainder of 228.
Use 4 as the next digit of our solution. 
Result so far: 20793.8174
Subtracting 1512 from 1740 leaves us with 228.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2280, and continue the process.

Advancing to step 12:
If we divide 2280 by 378, we get 6 and a remainder of 12.
Put 6 as the next digit of the answer. 
Result so far: 20793.81746
Deduct 2268 from 2280 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 13:
120 divided by 378 is 0 with a remainder of 120.
Record the quotient 0 as the next digit in the result. 
Result so far: 20793.81746
Subtracting 0 from 120 leaves us 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.

On to step 14:
If we divide 1200 by 378, we get 3 and a remainder of 66.
Write down 3 as next digit of the result. 
Result so far: 20793.8174603
Deduct 1134 from 1200 and we're left with 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Let's proceed to step 15:
378 goes into 660 1 times with a remainder of 282.
Use 1 as the next digit of our solution. 
Result so far: 20793.81746031
The remainder is 282 after subtracting 378 from 660.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2820, and continue the process.

The final outcome is 20793.81746031, with a leftover of 2.82e-07.