Calculator with stepwise display of linear equations

Abstract

An improved educational calculator permits sequential display of equations as transformations are made to solve the equations. First simultaneous linear equations are entered, and each time an advance key is depressed, process equations, obtained by transforming the equations step by step to reach their answers, are successively displayed on a liquid-crystal display screen. Each time a return key is depressed, the process equations are successively displayed from the answers to the equations in a reverse manner. The problem-solving method is selected through the entry of a solution key among the addition and subtraction method, the substitution method and the equivalence method, which are learned in the junior high school. The sequential display mode of the process equations can be switched between the automatic sequential display and the display on the basis of each entry of the advance key and the return key. Thus, it is possible to learn step by step the respective processes of the problem-solving methods of simultaneous linear equations. Even if there is an error in the answers found by the user, it is possible for the user to confirm at which step of the transformations he has erred, by operating the advance key and the return key. Thus, it becomes possible to provide educational equipment for junior high students that has superior effects of learning.