We look at the division of 15500156 by 123 
The aim is to understand the frequency of 123 in 15500156.

Step 1:
1 divided by 123 is 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Include the next digit (5) from the dividend after 1, then repeat: 15 / 123

Step 2:
15 divided by 123 is 0 with a remainder of 15.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 15 and we're left with 15.
Bring next digit (5) of the dividend behind the 15 and repeat the process: 155 / 123

Step 3:
If we divide 155 by 123, we get 1 and a remainder of 32.
The next digit of our result is 1. 
Result so far: 1.0
Subtract 123 from 155 to get 32.
Include the next digit (0) from the dividend after 32, then repeat: 320 / 123

Going ahead to step 4:
320 divided by 123 is 2 with a remainder of 74.
The next digit of our result is 2. 
Result so far: 12.0
If we subtract 246 from 320, we get 74.
Append the next digit (0) from the dividend to 74 and continue with: 740 / 123

On to step 5:
123 can be fit into 740 6 times, resulting in a remainder of 2.
Use 6 as the next digit of our solution. 
Result so far: 126.0
Deduct 738 from 740 and we're left with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 123

Advancing to step 6:
21 divided by 123 is 0 with a remainder of 21.
Use 0 as the next digit of our solution. 
Result so far: 1260.0
Subtracting 0 from 21 leaves us with 21.
Append the next digit (5) from the dividend to 21 and continue with: 215 / 123

Let's proceed to step 7:
If we divide 215 by 123, we get 1 and a remainder of 92.
The number 1 becomes the next digit in our result. 
Result so far: 12601.0
The remainder is 92 after subtracting 123 from 215.
Fetch the next digit (6) from the dividend, attach it to 92 and continue: 926 / 123

Step 8:
123 goes into 926 7 times with a remainder of 65.
Record the quotient 7 as the next digit in the result. 
Result so far: 126017.0
Subtract 861 from 926 to get 65.
Since there are no more digits in the dividend, we add a zero to the remainder making it 650, and continue the process.

On to step 9:
650 divided by 123 is 5 with a remainder of 35.
Write down 5 as next digit of the result. 
Result so far: 126017.5
Subtract 615 from 650 to get 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Going ahead to step 10:
123 goes into 350 2 times with a remainder of 104.
Use 2 as the next digit of our solution. 
Result so far: 126017.52
Subtracting 246 from 350 leaves us with 104.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1040, and continue the process.

Going ahead to step 11:
1040 divided by 123 is 8 with a remainder of 56.
Write down 8 as next digit of the result. 
Result so far: 126017.528
The remainder is 56 after subtracting 984 from 1040.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

Advancing to step 12:
123 can be fit into 560 4 times, resulting in a remainder of 68.
Put 4 as the next digit of the answer. 
Result so far: 126017.5284
Subtracting 492 from 560 leaves us with 68.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

Let's proceed to step 13:
If we divide 680 by 123, we get 5 and a remainder of 65.
Put 5 as the next digit of the answer. 
Result so far: 126017.52845
Subtract 615 from 680 to get 65.
Since there are no more digits in the dividend, we add a zero to the remainder making it 650, and continue the process.

Going ahead to step 14:
123 goes into 650 5 times with a remainder of 35.
The number 5 becomes the next digit in our result. 
Result so far: 126017.528455
Subtracting 615 from 650 leaves us with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

The final result is 126017.528455 with a remainder of 3.5e-06.