Let's divide 18459 by 42
Let's see how many times 42 fits into 18459.

Advancing to step 1:
When dividing 1 by 42, we get 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Append the next digit (8) from the dividend to 1 and continue with: 18 / 42

Advancing to step 2:
42 can be fit into 18 0 times, resulting in a remainder of 18.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 18 and we're left with 18.
Include the next digit (4) from the dividend after 18, then repeat: 184 / 42

Moving on to step 3:
When dividing 184 by 42, we get 4 with a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 4.0
Deduct 168 from 184 and we're left with 16.
Append the next digit (5) from the dividend to 16 and continue with: 165 / 42

Step 4:
When dividing 165 by 42, we get 3 with a remainder of 39.
The next digit of our result is 3. 
Result so far: 43.0
Deduct 126 from 165 and we're left with 39.
Append the next digit (9) from the dividend to 39 and continue with: 399 / 42

Going ahead to step 5:
399 divided by 42 is 9 with a remainder of 21.
Record the quotient 9 as the next digit in the result. 
Result so far: 439.0
Deduct 378 from 399 and we're left with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Moving on to step 6:
210 divided by 42 is 5 with a remainder of 0.
The next digit of our result is 5. 
Result so far: 439.5
If we subtract 210 from 210, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 7:
42 can be fit into 0 0 times, resulting in a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 439.5
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 8:
0 divided by 42 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 439.5
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 439.5, with a leftover of 0.0.