31398 ÷ 42 
Let's see how many times 42 fits into 31398.

Step 1:
The number 42 fits into 3 0 times, leaving a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Take the next digit (1) from the dividend and append it to 3, then repeat: 31 / 42

Let's proceed to step 2:
If we divide 31 by 42, we get 0 and a remainder of 31.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 31, we get 31.
Take the next digit (3) from the dividend and append it to 31, then repeat: 313 / 42

Step 3:
If we divide 313 by 42, we get 7 and a remainder of 19.
Put 7 as the next digit of the answer. 
Result so far: 7.0
If we subtract 294 from 313, we get 19.
Fetch the next digit (9) from the dividend, attach it to 19 and continue: 199 / 42

Moving on to step 4:
42 goes into 199 4 times with a remainder of 31.
The next digit of our result is 4. 
Result so far: 74.0
Subtracting 168 from 199 leaves us with 31.
Append the next digit (8) from the dividend to 31 and continue with: 318 / 42

Let's proceed to step 5:
The number 42 fits into 318 7 times, leaving a remainder of 24.
Use 7 as the next digit of our solution. 
Result so far: 747.0
Deduct 294 from 318 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Advancing to step 6:
The number 42 fits into 240 5 times, leaving a remainder of 30.
The next digit of our result is 5. 
Result so far: 747.5
Subtract 210 from 240 to get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Advancing to step 7:
300 divided by 42 is 7 with a remainder of 6.
The next digit of our result is 7. 
Result so far: 747.57
Subtracting 294 from 300 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 8:
The number 42 fits into 60 1 times, leaving a remainder of 18.
The next digit of our result is 1. 
Result so far: 747.571
If we subtract 42 from 60, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Going ahead to step 9:
If we divide 180 by 42, we get 4 and a remainder of 12.
The next digit of our result is 4. 
Result so far: 747.5714
If we take 168 away from 180, 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 10:
The number 42 fits into 120 2 times, leaving a remainder of 36.
The number 2 becomes the next digit in our result. 
Result so far: 747.57142
Deduct 84 from 120 and we're left with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Going ahead to step 11:
42 goes into 360 8 times with a remainder of 24.
Record the quotient 8 as the next digit in the result. 
Result so far: 747.571428
Subtracting 336 from 360 leaves us with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

On to step 12:
When dividing 240 by 42, we get 5 with a remainder of 30.
The number 5 becomes the next digit in our result. 
Result so far: 747.5714285
Subtracting 210 from 240 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 13:
42 goes into 300 7 times with a remainder of 6.
Write down 7 as next digit of the result. 
Result so far: 747.57142857
The remainder is 6 after subtracting 294 from 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

The quotient of the division is 747.57142857, and the remainder is 6e-09.