Why is round() returning a wrong answer and how do I fix it?

Asked Jan 09 '20 at 12:17

Active Jan 09 '20 at 12:21

Viewed 40 times

I'm trying to solve a simple challenge that requires the code to return numbers (floats) rounded to 1 decimal point(s). The code is actually working but it seems that round() is not returning the correct result.

For example, the answer to one of the test cases I'm getting is 45357.45. When rounded to the first decimal, this should be 45357.5. But using round() is still returning 45357.4. I tested with the following numbers and I'm getting mixed results:

# Correct
print(round(5.45, 1))
5.5

# Incorrect
print(round(5674.45, 1))
5674.4

Why would this happen and is there a way to fix it?

edited Jan 09 '20 at 12:21

accdias

5,160
3
19
31

asked Jan 09 '20 at 12:17

shiv_90

1,025
3
12
35

http://floating-point-gui.de – deceze Jan 09 '20 at 12:19
1

https://stackoverflow.com/questions/588004/is-floating-point-math-broken – Łukasz Rogalski Jan 09 '20 at 12:20
`print(5674.45, 1)` Did you mean `print(round(5674.45, 1))` ? – Cid Jan 09 '20 at 12:20
1

If you write 5674.45 in your code, you get a number equal to around `5674.449999...`. Because floating point numbers are approximations. – khelwood Jan 09 '20 at 12:21
Sorry for the typo. My brain is fried and I need some nap :) – shiv_90 Jan 09 '20 at 12:21

Why is round() returning a wrong answer and how do I fix it?

0 Answers0