Question

 why is 0.5%  not equal to 1/2?

Answer 1

It is not equal to 1/2 because .5% is indeed a percent, and therefore a fraction of 100. If you were to rewrite .5% as a fraction, you would write it as 5/100, which simplifies to 1/20, which is nowhere near 1/2. 50% or .5 would be equal to 1/2.

Answer 2

because 1/2 is equal to 50%

0.5≠50