We look at the division of 515454 by 3 
Let's see how many times 3 fits into 515454.

Step 1:
If we divide 5 by 3, we get 1 and a remainder of 2.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Deduct 3 from 5 and we're left with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 3

Moving on to step 2:
The number 3 fits into 21 7 times, leaving a remainder of 0.
Put 7 as the next digit of the answer. 
Result so far: 17.0
Subtracting 21 from 21 leaves us with 0.
Append the next digit (5) from the dividend to 0 and continue with: 5 / 3

On to step 3:
If we divide 5 by 3, we get 1 and a remainder of 2.
Use 1 as the next digit of our solution. 
Result so far: 171.0
If we take 3 away from 5, we end up with 2.
Fetch the next digit (4) from the dividend, attach it to 2 and continue: 24 / 3

Going ahead to step 4:
The number 3 fits into 24 8 times, leaving a remainder of 0.
Use 8 as the next digit of our solution. 
Result so far: 1718.0
If we subtract 24 from 24, we get 0.
Fetch the next digit (5) from the dividend, attach it to 0 and continue: 5 / 3

On to step 5:
The number 3 fits into 5 1 times, leaving a remainder of 2.
Write down 1 as next digit of the result. 
Result so far: 17181.0
Subtract 3 from 5 to get 2.
Bring next digit (4) of the dividend behind the 2 and repeat the process: 24 / 3

On to step 6:
The number 3 fits into 24 8 times, leaving a remainder of 0.
Put 8 as the next digit of the answer. 
Result so far: 171818.0
Subtracting 24 from 24 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.

Advancing to step 7:
3 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 171818.0
If we take 0 away from 0, 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.

Advancing to step 8:
If we divide 0 by 3, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 171818.0
If we take 0 away from 0, 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.

The final outcome is 171818.0, with a leftover of 0.0.