to such skilled persons a calculator constructed in accordance with a preferred embodiment of the invention is illustrated in fig1 and generally designated 10 the calculator includes a keyboard or other input means 12 and a display or other display means 14 the keyboard 12 includes several groups of keys including power and clear keys 16 numeric keys 18 measurement keys 20 a conversion key 22 and a percentage key 24 secondary functions are accessed through the numeric keys 18 and are displayed on the calculator housing 26 the power clear keys 16 are conventional and are used to turn the calculator on and off and to clear the display and or clear memory the on c or on clear key turns power on pressing once clears the display pressing twice clears all temporary values the off or off key turns all power off clearing all non permanent registers the numeric keys 18 are conventional and used to input numeric information and include the conventional numeric keys 0 9 and a decimal point dimensional keys 20 are conventional and are used to label or convert entered values into appropriate dimensional values to label a dimension as u201c square u201d or u201c cubic u201d the value is entered and then the desired key is pressed twice to square and three times to cube for example to enter 25 cubic yards the user presses 25 yds yds yds to enter 25 square feet the user.