# Online Math Dictionary: A

Easy to understand math definitions for K-Algebra mathematics
Just scroll down or click on the word you want and I'll scroll down for you!

 abacus absolute value acceleration acre acute angle addend additive identity additive inverse adjacent algebra algorithm alternate exterior angles alternate interior angles alternating sequence amplitude angle annual annuity arc area arithmetic associative property of addition associative property of multiplication average axiom axis of symmetry

 AbacusAn abacus is an ancient  calculating device used for addition, subtraction, multiplication, division, square roots and cube roots.   It's  still used today in some countries.  Absolute Value
An absolute value is a number's distance from zero on the number line.
Examples:   | 0 | =         | 5 | = 5       | -3 | = 3
For more information on absolute values, check out my Absolute Value Review lesson. Acceleration
Acceleration is the change in something's speed (velocity).  When you are speeding up, you are accelerating.  When you are slowing down, you are "accelerating" - well, that's what they'd say in a Physics class, but we say "decelerating." Acre
An acre is a unit of measure used for measuring land in the United States.  An acre is 43,560 square feet or 4,840 square yards.