Digital Workshop

Hello,
I am a New Zealand biology and chemistry teacher. I teach biology to Year 13 (final high school year) and chemistry to year 12. I am interested in any Opus scripts for simple chemical calculations, such as titration, mole calculations, percentage composition and empirical formulas. If anyone has any of these ready made scripts and is willing to share them with me, I would be very grateful. I have produced a Year 13 Biology Companion and also a Year 9 and 10 Science CD of roughly 18 MB each. I hope to sell the Year 13 Biology to New Zealand High School students at $NZ25 (about 10 pounds?), but I do give the Year 9 and 10 CD to anyone that wants it. (provided that I do not get 50 people wanting copies). My name is David Layzell and my email address is layzelld@xtra.co.nz.