Why the output is false

Question

a = 0.1
b = 0.2
c = 0.3
print(a+b==c)

Answer 1

Because it's in float value the calculation internally will change value in decimal terms with the c value which is leading to false as the answer. Hence you can use round function to round to 1 to get true as answer

Example a = round(value, roundoff_value)

Answer 2

Isn't 0.1+0.2 = 0.3

🤔🤔

Answer 3

Rahul Bankar ,

in many cases this issue does not matter if it is possible to do rounding.

however there are reasons that the precission matters. in this case we can use a different numerical data format `decimals`. (decimal module is shipped with the python installation):

https://sololearn.com/compiler-playground/c2CXgHef0K0G/?ref=app

Answer 4

Rahul Bankar here is similar code with explanation in the comments:

https://sololearn.com/compiler-playground/cda62498xsW9/?ref=app

Answer 5

Brian ,

it is not just fun to read all of these comments and figure out what is true or what is an assumption 🤣

Answer 6

https://sololearn.com/compiler-playground/cUYHw2KG6Ws1/?ref=app

I believe its because your trying to use a base-10 system on a base-2 system (binary). You can only express fractions of a base by using its prime factors. The prime fractors of 10 are 2 and 5. So fractions like 1/2, 1/4, 1/8, 1/10,…. these numbers will result in a nice rounded number. If you were to do numbers whose fractions were 1/3,1/6,1/9, then you will get repeated numbers.

Computers use binary, so they use a base-2 system. The prime fractors for 2 is…2. So only fractions like 1/2,1/4,1/8 result in nice clean numbers. 1/5 and 1/10 are repeated because there prime factor is 5.

For repeated numbers, computers can’t write an infinite amount of something so the numbers are rounded off.

https://0.30000000000000004.com