| 摘要 |
<p>A learning aid for teaching arithmetic skills, that functions without an external source of electricity and weighs less than one kilogram, poses sets of problems to a user. The device has a question-probability-setting selector which allows the user to select-for practicing or testing-from among different groups of problems in which different problems have different probabilities of being posed. The device can pose sets of recently-missed questions by means of a missed-questions memory that stores a limited number of questions that a user-during one or more sets of questions-has most recently either answered incorrectly or failed to answer within a per-question time limit. The device generates an evaluative question-set score based on how well the user has answered a set of questions posed by it and stores and displays, one at a time, the scores for a limited number of the most recent question sets. Furthermore, the device continues to store the most recent scores and most recently missed questions even when its main power is turned off.</p> |
