Absolute Magnitudes for Cepheids

[sailof]

Would somebody help me in entering a calculation into my scientific calculator?
The equation is Mv = - [2.76 log10(P) – 1.0)] – 4.16
I have the value of P but I'm not sure how to enter this into the calculator. I get a different answer every time.
Thanks,

 

[hage567]

Can you tell us what P is, and some of the answers you are getting? Maybe we can spot what you're doing wrong. What did you get for the 2.76logP part?

 

[sailof]

I'm solving for absolute magnitudes for Cepheids. For my first Cepheid P is 50.0 and my first response was -9.34 but I think I forgot to enter the negative sign at the beginning of the equation.
thank you.