84213130 ÷ 123 
The aim is to understand the frequency of 123 in 84213130.

On to step 1:
8 divided by 123 is 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Include the next digit (4) from the dividend after 8, then repeat: 84 / 123

Going ahead to step 2:
When dividing 84 by 123, we get 0 with a remainder of 84.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 84, we end up with 84.
Take the next digit (2) from the dividend and append it to 84, then repeat: 842 / 123

Going ahead to step 3:
If we divide 842 by 123, we get 6 and a remainder of 104.
Write down 6 as next digit of the result. 
Result so far: 6.0
If we take 738 away from 842, we end up with 104.
Bring next digit (1) of the dividend behind the 104 and repeat the process: 1041 / 123

Advancing to step 4:
The number 123 fits into 1041 8 times, leaving a remainder of 57.
Record the quotient 8 as the next digit in the result. 
Result so far: 68.0
If we take 984 away from 1041, we end up with 57.
Bring next digit (3) of the dividend behind the 57 and repeat the process: 573 / 123

Moving on to step 5:
123 goes into 573 4 times with a remainder of 81.
Put 4 as the next digit of the answer. 
Result so far: 684.0
The remainder is 81 after subtracting 492 from 573.
Include the next digit (1) from the dividend after 81, then repeat: 811 / 123

Going ahead to step 6:
If we divide 811 by 123, we get 6 and a remainder of 73.
Write down 6 as next digit of the result. 
Result so far: 6846.0
The remainder is 73 after subtracting 738 from 811.
Include the next digit (3) from the dividend after 73, then repeat: 733 / 123

Let's proceed to step 7:
123 goes into 733 5 times with a remainder of 118.
Put 5 as the next digit of the answer. 
Result so far: 68465.0
If we subtract 615 from 733, we get 118.
Include the next digit (0) from the dividend after 118, then repeat: 1180 / 123

Advancing to step 8:
123 goes into 1180 9 times with a remainder of 73.
The next digit of our result is 9. 
Result so far: 684659.0
If we take 1107 away from 1180, we end up with 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Let's proceed to step 9:
730 divided by 123 is 5 with a remainder of 115.
Put 5 as the next digit of the answer. 
Result so far: 684659.5
Deduct 615 from 730 and we're left with 115.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1150, and continue the process.

Step 10:
1150 divided by 123 is 9 with a remainder of 43.
The next digit of our result is 9. 
Result so far: 684659.59
The remainder is 43 after subtracting 1107 from 1150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Let's proceed to step 11:
123 can be fit into 430 3 times, resulting in a remainder of 61.
Write down 3 as next digit of the result. 
Result so far: 684659.593
Subtract 369 from 430 to get 61.
Since there are no more digits in the dividend, we add a zero to the remainder making it 610, and continue the process.

Going ahead to step 12:
123 goes into 610 4 times with a remainder of 118.
Write down 4 as next digit of the result. 
Result so far: 684659.5934
Subtracting 492 from 610 leaves us with 118.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1180, and continue the process.

Let's proceed to step 13:
When dividing 1180 by 123, we get 9 with a remainder of 73.
The next digit of our result is 9. 
Result so far: 684659.59349
If we subtract 1107 from 1180, we get 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Advancing to step 14:
730 divided by 123 is 5 with a remainder of 115.
Put 5 as the next digit of the answer. 
Result so far: 684659.593495
Subtract 615 from 730 to get 115.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1150, and continue the process.

Advancing to step 15:
123 can be fit into 1150 9 times, resulting in a remainder of 43.
The number 9 becomes the next digit in our result. 
Result so far: 684659.5934959
Subtracting 1107 from 1150 leaves us with 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Step 16:
If we divide 430 by 123, we get 3 and a remainder of 61.
The next digit of our result is 3. 
Result so far: 684659.59349593
If we take 369 away from 430, we end up with 61.
Since there are no more digits in the dividend, we add a zero to the remainder making it 610, and continue the process.

In conclusion, the division gives 684659.59349593 with a balance of 6.1e-08.