Texas Instruments TI30XA Scientific Calculator for $12.05

Once you get to a certain level of math classes, a regular old calculator just isn't good enough anymore--you need a high-functioning calculator that can perform algebraic, trigonometric, and statistical problems in addition to general mathematical tasks. The Texas Instruments TI-30XA scientific calculator can do this for you. It is extremely handy when it comes to figuring tricky fractions. It can add, subtract, multiply, and divide fractions when entered in a traditional numerator/denominator format.