Here are some websites to help with your math:
http://web2.0calc.com/ On-line Scientific calculator that you can use.
http://www.mathopenref.com/calculator.html On-line scientific calculator that you an use.
http://www.onlineconversion.com/ Conversion for just about anything-great for Science too!
http://www.aaamath.com/plc.htm sorted by grade level on various math topics.