123959 divided by 42 
Let's see how many times 42 fits into 123959.

Going ahead to step 1:
42 can be fit into 1 0 times, resulting in a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 42

On to step 2:
42 can be fit into 12 0 times, resulting in a remainder of 12.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 12, we get 12.
Fetch the next digit (3) from the dividend, attach it to 12 and continue: 123 / 42

Let's proceed to step 3:
123 divided by 42 is 2 with a remainder of 39.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
Deduct 84 from 123 and we're left with 39.
Bring next digit (9) of the dividend behind the 39 and repeat the process: 399 / 42

Going ahead to step 4:
If we divide 399 by 42, we get 9 and a remainder of 21.
The next digit of our result is 9. 
Result so far: 29.0
Subtract 378 from 399 to get 21.
Append the next digit (5) from the dividend to 21 and continue with: 215 / 42

Step 5:
When dividing 215 by 42, we get 5 with a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 295.0
Deduct 210 from 215 and we're left with 5.
Bring next digit (9) of the dividend behind the 5 and repeat the process: 59 / 42

Step 6:
42 can be fit into 59 1 times, resulting in a remainder of 17.
The next digit of our result is 1. 
Result so far: 2951.0
The remainder is 17 after subtracting 42 from 59.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Advancing to step 7:
42 goes into 170 4 times with a remainder of 2.
Write down 4 as next digit of the result. 
Result so far: 2951.4
Subtracting 168 from 170 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 8:
20 divided by 42 is 0 with a remainder of 20.
Put 0 as the next digit of the answer. 
Result so far: 2951.4
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 9:
42 can be fit into 200 4 times, resulting in a remainder of 32.
The next digit of our result is 4. 
Result so far: 2951.404
Subtracting 168 from 200 leaves us with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

On to step 10:
42 can be fit into 320 7 times, resulting in a remainder of 26.
Record the quotient 7 as the next digit in the result. 
Result so far: 2951.4047
Deduct 294 from 320 and we're left with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

On to step 11:
42 can be fit into 260 6 times, resulting in a remainder of 8.
Put 6 as the next digit of the answer. 
Result so far: 2951.40476
Subtracting 252 from 260 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 12:
80 divided by 42 is 1 with a remainder of 38.
Put 1 as the next digit of the answer. 
Result so far: 2951.404761
If we take 42 away from 80, we end up with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Advancing to step 13:
380 divided by 42 is 9 with a remainder of 2.
The number 9 becomes the next digit in our result. 
Result so far: 2951.4047619
Subtract 378 from 380 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Step 14:
The number 42 fits into 20 0 times, leaving a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 2951.4047619
If we subtract 0 from 20, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

In conclusion, the division gives 2951.4047619 with a balance of 2e-08.