US 6,557,018 B1Granted

Desk calculator capable of easy checking and trustworthy calculation

OwnerHiroyuki Shibasakiinventor

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Abstract

A electronic calculator in which inputted calculating data consisted of alternately appearing operators and numerical values is maintained very reliable, and with which users can execute very trustworthy sequential works of confirming and restarting calculation very steadily, even after suspending the calculation process at any time in order to confirm or correct inputted calculating items. This calculator is provided with a means of inhibiting reopening of such an input that is not able to maintain consistency that operators and numerical values alternately appear, and a means for resuming the calculation by canceling the inhibition maintaining the consistency that operators and numerical values alternately appear, besides with a memory means for storing each inputted calculating item, and a means for displaying them with the numbers and the total number of them for confirmation, and a means for making them correctable.

Claims9

Dependent claims

An electronic calculator comprising:

memory means which stores each inputted calculating item consisted of an operator and a numerical value into input history storing memory at ordinary calculator mode;
means for displaying each calculating item stored into input history storing memory at input history display mode;
means for making each displayed calculating item stored into input history storing memory correctable;
recalculation means which automatically calls stored calculating item one after another from the first for recalculation and shows answer of the recalculation;
and further
means which, at ordinary calculation course and after recalculation, inhibits such an input that is not able to maintain such consistency in input history storing memory that operators and numerical values alternately appear, and
means for resuming calculation and storing of calculating item following next by canceling the inhibition maintaining consistency in input history storing memory that operators and numerical values alternately appear.

4 more elements

Dependencies are inferred from the claim text.