We divide 309978 by 20
We want to divide 309978 by 20.

Let's proceed to step 1:
The number 20 fits into 3 0 times, leaving a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Grab the next digit (0) from the dividend, add it to 3, then carry on: 30 / 20

Step 2:
20 goes into 30 1 times with a remainder of 10.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtracting 20 from 30 leaves us with 10.
Fetch the next digit (9) from the dividend, attach it to 10 and continue: 109 / 20

Step 3:
If we divide 109 by 20, we get 5 and a remainder of 9.
Use 5 as the next digit of our solution. 
Result so far: 15.0
If we subtract 100 from 109, we get 9.
Bring next digit (9) of the dividend behind the 9 and repeat the process: 99 / 20

Let's proceed to step 4:
20 can be fit into 99 4 times, resulting in a remainder of 19.
The next digit of our result is 4. 
Result so far: 154.0
Subtract 80 from 99 to get 19.
Fetch the next digit (7) from the dividend, attach it to 19 and continue: 197 / 20

Let's proceed to step 5:
If we divide 197 by 20, we get 9 and a remainder of 17.
The number 9 becomes the next digit in our result. 
Result so far: 1549.0
If we take 180 away from 197, we end up with 17.
Include the next digit (8) from the dividend after 17, then repeat: 178 / 20

Step 6:
If we divide 178 by 20, we get 8 and a remainder of 18.
Write down 8 as next digit of the result. 
Result so far: 15498.0
If we subtract 160 from 178, 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.

On to step 7:
20 goes into 180 9 times with a remainder of 0.
Record the quotient 9 as the next digit in the result. 
Result so far: 15498.9
If we take 180 away from 180, we end up with 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:
If we divide 0 by 20, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 15498.9
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.

Advancing to step 9:
20 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 15498.9
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.

The final result is 15498.9 with a remainder of 0.0.