ABSTRACT
This chapter presents a calculator to add, subtract, multiply and divide decimal numbers and explores the calculator to evaluate square, cube, reciprocal, power, root and × 10x functions. It examines a calculator to evaluate expressions containing fractions and trigonometric functions and aims to evaluate formulae, given values. In engineering, calculations often need to be performed. For simple numbers it is useful to be able to use mental arithmetic. However, when numbers are larger an electronic calculator needs to be used. There are several calculators on the market, many of which will be satisfactory for our needs. It is essential to have a scientific notation calculator which will have all the necessary functions needed, and more.
