42456717 ÷ 123 
We're looking to find how many times 123 goes into 42456717.

On to step 1:
When dividing 4 by 123, we get 0 with a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Append the next digit (2) from the dividend to 4 and continue with: 42 / 123

On to step 2:
123 goes into 42 0 times with a remainder of 42.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 42 and we're left with 42.
Append the next digit (4) from the dividend to 42 and continue with: 424 / 123

On to step 3:
The number 123 fits into 424 3 times, leaving a remainder of 55.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
The remainder is 55 after subtracting 369 from 424.
Take the next digit (5) from the dividend and append it to 55, then repeat: 555 / 123

Going ahead to step 4:
123 goes into 555 4 times with a remainder of 63.
Use 4 as the next digit of our solution. 
Result so far: 34.0
The remainder is 63 after subtracting 492 from 555.
Fetch the next digit (6) from the dividend, attach it to 63 and continue: 636 / 123

On to step 5:
123 goes into 636 5 times with a remainder of 21.
Put 5 as the next digit of the answer. 
Result so far: 345.0
Subtract 615 from 636 to get 21.
Fetch the next digit (7) from the dividend, attach it to 21 and continue: 217 / 123

Step 6:
When dividing 217 by 123, we get 1 with a remainder of 94.
The number 1 becomes the next digit in our result. 
Result so far: 3451.0
The remainder is 94 after subtracting 123 from 217.
Include the next digit (1) from the dividend after 94, then repeat: 941 / 123

Advancing to step 7:
123 can be fit into 941 7 times, resulting in a remainder of 80.
Use 7 as the next digit of our solution. 
Result so far: 34517.0
Subtracting 861 from 941 leaves us with 80.
Fetch the next digit (7) from the dividend, attach it to 80 and continue: 807 / 123

Let's proceed to step 8:
The number 123 fits into 807 6 times, leaving a remainder of 69.
Record the quotient 6 as the next digit in the result. 
Result so far: 345176.0
Subtract 738 from 807 to get 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Moving on to step 9:
690 divided by 123 is 5 with a remainder of 75.
Record the quotient 5 as the next digit in the result. 
Result so far: 345176.5
Deduct 615 from 690 and we're left with 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Going ahead to step 10:
123 goes into 750 6 times with a remainder of 12.
Put 6 as the next digit of the answer. 
Result so far: 345176.56
If we take 738 away from 750, we end up 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.

Step 11:
When dividing 120 by 123, we get 0 with a remainder of 120.
Write down 0 as next digit of the result. 
Result so far: 345176.56
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 12:
123 goes into 1200 9 times with a remainder of 93.
Record the quotient 9 as the next digit in the result. 
Result so far: 345176.5609
Subtract 1107 from 1200 to get 93.
Since there are no more digits in the dividend, we add a zero to the remainder making it 930, and continue the process.

Moving on to step 13:
930 divided by 123 is 7 with a remainder of 69.
The number 7 becomes the next digit in our result. 
Result so far: 345176.56097
If we subtract 861 from 930, we get 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

On to step 14:
If we divide 690 by 123, we get 5 and a remainder of 75.
Record the quotient 5 as the next digit in the result. 
Result so far: 345176.560975
If we take 615 away from 690, we end up with 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Step 15:
The number 123 fits into 750 6 times, leaving a remainder of 12.
Record the quotient 6 as the next digit in the result. 
Result so far: 345176.5609756
Deduct 738 from 750 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.

On to step 16:
120 divided by 123 is 0 with a remainder of 120.
Write down 0 as next digit of the result. 
Result so far: 345176.5609756
Deduct 0 from 120 and we're left 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.

The final outcome is 345176.5609756, with a leftover of 1.2e-07.