CAHSEE Prep - Tutorial sources by Topic - Number Sense
Math Glossary (more sophisticated than it looks!)
Scientific notation
Scientific Notation lesson - ETAP.org ETAP Pretest
Scientific Notation lesson - RegentsPrep.org ETAP Posttest
Rational numbers
Rational Numbers - ETAP.org ETAP Pretest
Rational Numbers - RegentsPrep.org ETAP Posttest
Convert fractions to decimals
Converting Fractions to Decimals - ETAP.org ETAP Pretest
Converting Fractions to Decimals - Learningwave.com ETAP Posttest
Percentage calculations
Percentage Calculations - RegentsPrep.org  
Solve problems involving discounts, markups, commissions
 Word problems with discounts/markups/commissions - PurpleMath.com  
Multiply and divide expressions involving exponents
Multiply and divide exponential expressions - RegentsPrep.org  
Multiply, divide and simplify rational numbers
Multiply/Divide/Simplify Rational Numbers - RegentsPrep.org  
Raising to a power and square roots
Raising to a Power/Square Roots - RegentsPrep.org  
Absolute Value
Absolute Value - RegentsPrep.org  

Online Scientific Calculator from Calculator.com

Math Glossary
(more sophisticated than it looks!)