float multiplication - unexpected output

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float multiplication - unexpected output - inesk - Dec-11-2018

Hello,

I have a unexpected output on a simple multiplication:

0.55*50000

Output:
27500.000000000004

While if I run an equivalent expression

0.55*5*10000

Output:
27500.0

Which is the right output. Is is also the case for other expressions like : 0.55*100 that gives: 55.00000000000001
Anybody knows what this is due to ?

Many thanks,

Inès

RE: float multiplication - unexpected output - Larz60+ - Dec-11-2018

floating point is multiplication of two numbers, an integer times an exponent and therefore is a close approximation, not exact

Quote:Which is the right output.

Both are in their situation.

RE: float multiplication - unexpected output - Gribouillis - Dec-11-2018

See this thread or this one

RE: float multiplication - unexpected output - DeaD_EyE - Dec-11-2018

You need to learn more about floating point numbers.
Floating point numbers can't represent all decimal fractions.

import webbrowser
webbrowser.open(str(0.1 + 0.2) + '.com')

http://0.30000000000000004.com/

If you need something, which does not have this problem: decimal fractions