InfoPath Dev

I am trying to create a rule that happens when someone makes a specific choice from a drop down menu. I can do this with input values, etc. but I can't figure out how to qualify the choice in the drop down. Thank you InfoPath gurus for all your help to newbies like me. Kris

Can I multiply and divide in InfoPath? If so, please let me know how. I am trying to create a form that will calculate the premiums and need these features to do it. I am so very new at this and cannot tell you how much I appreciate your assistance. Thank you!  Kris Kohn

I am VERy new to InfoPath and am trying to create a form which will sum a group of fields. I put the desired fields into a group, and then summed the group. But now, I put values in the grouped fields and I get no total. I am just a poor HR trying to create a form. Someone please help me! Also, does InfoPath have the ability to subtract, multiply ...