Take a look at the Algebra 1 - Algebra 2 - Precalculus - Calculus sequence by Paul A. Foerster and the text: Geometry: A Guided Inquiry by Chakerian, Crabill, and Stein. I have been recording lessons based on these texts for homeschoolers. They might be suitable for you too. I chose to work...
Density of Water
As I understand it, the gram was defined as the mass of 1 cm^3 of water (at 4°C). That would make 1 liter of water exactly 1 kg. Where are you getting the .96 figure?