本研究主要在了解閱讀障礙兒童和數學學習障礙兒童在數學心算能力上和普通兒 童是否不同。而其不同是否與數字記憶廣度有關。在本研究中，分別以「修訂魏氏兒童智力 測驗」中的數字記憶廣度測驗及研究者自編的心算測驗測量三組的數字記憶度及心算能力， 並將受試心算測驗過程加以錄影。結果發現，閱讀障礙兒童及數學學障兒童在心算測驗上得 分比正常兒童差，但在數字記憶廣度測驗得分上，僅有數學學習障礙兒童在逆向數字記憶廣 度測驗得分和正常兒童有差異，因此數字記憶廣度可能不是造成其數學成績差異的主要原因 。而就錄影結果來看，閱讀障礙兒童及數學學習障礙兒童均較普通兒童常用口語以外的計算 方式計算數學。此外，就所有受試的數字記憶廣度成績及心算測驗成績進行相關分析，發現 有非常顯著相關，此點，似乎支持了 Baddeley 的運作記憶模式，但詳細的可能性仍待進一 步的研究來證實。

　　　　　This study wish to understand the dyslexia children and the dyscalculia children's digit span and mental calculation if different from the normal children, and if the difference has correlation to the digit span. In the study, using the "WISC"'s digit span test and mental calculation test which written by the writter test the three groups' digit span and mental calculation, and took a video photograph during the mental calculation test.In the result, the dyslexia children and the dyscalculia children's mental calculation test were worse than the normal children. In the digit span test, there were only dyscalculia children's against digit span had difference with the normal children. So, digit span may not be the important factor which makes the math grades different. In the result of VCR, the dyslexia children and the dyscalcuia children used the way beside colloquial to count more often than the normal ones.Besides,all the subjects' digit span test and mental calculation test's correlation reach the level of very significance. This seem supports Baddeley's working memory model.