Arithmetic Patents (Class 434/191)
  • Patent number: 4251093
    Abstract: A restaurant check and method for recording and totalling itemized food costs comprising a sheet for receiving indicia having an operative format of separately delineated digit columns and a stepwise array of cell groups aligned below the vertical columns for a two step additive method of first recording complete totals of each vertical column in cell groups of the stepwise array and then summing the recorded column totals from the stepwise array in a horizontal cell row.
    Type: Grant
    Filed: February 2, 1979
    Date of Patent: February 17, 1981
    Inventor: Philip C. Tobin
  • Patent number: 4247895
    Abstract: A calculator-type educational device for teaching arithmetic which provides features to motivate a student to greater learning progress including means for reporting the student's arithmetic proficiency by means of post-test statistics that are displayed after completion of a problem set. A dual mode of operation is provided, namely, a first mode in which a selected number of problems is presented for a student to solve at his own pace without any specified time limit and a second mode in which the student is presented problems in a specified period of time, the number of problems being determined solely by how rapidly the student can offer a proposed solution to each such problem.An additional unique feature of the present invention is the availability of numerical limits and factor multiples to which the problem parameters are related.The disclosed embodiment incorporates a microprocessor-based programmed computer in a desk-type calculator configuration.
    Type: Grant
    Filed: March 9, 1979
    Date of Patent: January 27, 1981
    Inventor: Randy C. Weber