Newb needs macro help.

Let's see, where to start...

Ok, I've got cells B5 thru B7 running different formulas based on data entered into cells B1 thru B3.
I've got each formula set to run only when the three cells contain data. (so if any one cell is blank, none of the formulas give a result).

Still with me? Good.

I've also got a "button" assigned with a macro that will clear the contents of B1:B3 when pressed.
I've got a second "button" that I'm WANTING to assign a macro that will do the following:

I want the formulas in cells B5:B7 to run ONLY when the "calculate" button is pressed. If the user enters data into B1, 2 and 3 then hits "calculate", the formulas should show their results. If the user enters different data without pressing "clear", I don't want the formulas to "auto run" like they would do by default.

I hope this make sense to you guys.
I'm going nuts trying to learn macros...

Attached is the file I'm working with so you can better visualize the stuff I've described above.

Thanks for all the help!