Accessible Calculators

Abstract

Calculators are one of the most commonly required tools at home, school and work, however, people with disabilities may have difficulty using standard calculators. Buttons on most calculators are smooth, and offer few or no tactile clues to allow a person with a visual impairment to orient him or herself to the keypad. People with visual impairments may not be able to see the appropriate buttons. Modern calculators generally have an LCD output screen, but these are often difficult to see as character size is generally small, and the contrast between the numerals and background is low. People with mobility impairments or tremor are often unable to touch individual buttons accurately on compact calculators with small buttons. Calculators may perform basic calculations or be suitable for statistical, scientific, or financial calculations. Scientific calculators compute logarithms, sine, cosine, tangent, pi, square root, and exponents. Algebraic calculators and graphing calculators can simplify algebraic expressions; differentiate, integrate, and plot functions; solve equations; and manipulate matrices. Statistical calculators compute statistical equations, including means, variances, covariance, and correlation and regression coefficients. Financial calculators compute present value and internal-rate-of-return, depreciation, and schedules such as amortization and future value. Use requirements vary from simple direct keystroke calculation to complex multi-keystroke combinations. Calculators are available with features that range from simple to complex, and which are offered in a variety of combinations. Features include adjustable angle display, large numbers, large buttons, printing capability in black or color and speech output in a range of voices. The products described in this article are only a few of the many calculators available on the market today. The companies listed may also make or distribute other calculators that could not be included due to space limitations. Contact individual companies for more information.