Khan Academy
Khan Academy: Algebra: Arithmetic With Polynomials and Rational Expressions
Understand that polynomials form a system analogous to the integers, namely, they are closed under the operations of addition, subtraction, and multiplication i.e. one can add, subtract, and multiply polynomials.
Calculator Soup
Calculator Soup: Mixed Numbers Calculator
Do math calculations with mixed numbers (mixed fractions) performing operations on fractions, whole numbers, integers, mixed numbers, mixed fractions, and improper fractions. This calculator can add, subtract, multiply and divide mixed...
Khan Academy
Khan Academy: Least Common Multiple
Find the lcm (least common multiple) of pairs of integers. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Wyzant
Wyzant: Simplifying Multiple Signs Worksheet
Dealing with multiple positive and negative signs in an algebra equation can be a challenge for some students. This inter-active quiz from WyzAnt provides 20 multiple-sign equations and their answers for students to test their knowledge.