We look at the division of 343454 by 20 
Let's see how many times 20 fits into 343454.

Going ahead to step 1:
If we divide 3 by 20, we get 0 and a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Append the next digit (4) from the dividend to 3 and continue with: 34 / 20

Going ahead to step 2:
When dividing 34 by 20, we get 1 with a remainder of 14.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtract 20 from 34 to get 14.
Include the next digit (3) from the dividend after 14, then repeat: 143 / 20

Step 3:
143 divided by 20 is 7 with a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 17.0
Deduct 140 from 143 and we're left with 3.
Include the next digit (4) from the dividend after 3, then repeat: 34 / 20

On to step 4:
20 goes into 34 1 times with a remainder of 14.
The number 1 becomes the next digit in our result. 
Result so far: 171.0
Deduct 20 from 34 and we're left with 14.
Grab the next digit (5) from the dividend, add it to 14, then carry on: 145 / 20

Advancing to step 5:
If we divide 145 by 20, we get 7 and a remainder of 5.
Use 7 as the next digit of our solution. 
Result so far: 1717.0
Deduct 140 from 145 and we're left with 5.
Grab the next digit (4) from the dividend, add it to 5, then carry on: 54 / 20

Step 6:
20 goes into 54 2 times with a remainder of 14.
Use 2 as the next digit of our solution. 
Result so far: 17172.0
If we subtract 40 from 54, we get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Step 7:
The number 20 fits into 140 7 times, leaving a remainder of 0.
Use 7 as the next digit of our solution. 
Result so far: 17172.7
Subtract 140 from 140 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.

Step 8:
The number 20 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 17172.7
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.

On to step 9:
If we divide 0 by 20, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 17172.7
Subtracting 0 from 0 leaves us 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.

Our division results in 17172.7 with a remaining 0.0.