Inventors:
Roy W. Reach - Sudbury MA
William M. Kahn - Brighton MA
David Shapiro - Lincoln MA
Assignee:
Hewlett-Packard Company - Palo Alto CA
International Classification:
G06F 302, G06F 314, G06F 738
Abstract:
An algebraic electronic calculator is provided having a keyboard input unit with digit keys for entering numbers into the calculator and control keys for entering add, subtract, multiply, divide, left parenthesis, right parenthesis, storage register designating, square root, equals, and other operators into the calculator. A record of each number and operator entered into the calculator is printed out by an output printer so that a mathematical problem may be continuously monitored as it is being entered into the calculator. Depression of the square root control key initiates computation of the square root of a number stored in the calculator and printout of the result. The calculator also includes provision for computation of another such unary function such as cube root if desired. Depression of the equals control key is accompanied by evaluation of all the previously entered numbers and operators and printout of the results. Provision is made in the calculator for learning a sequence of operators as they are entered into the calculator during manually-controlled evaluation of a mathematical problem and for subsequently automatically evaluating such a mathematical problem in accordance with the learned sequence of operators.