"計算機" "並非數字" "錯誤" "." "0" "1" "2" "3" "4" "5" "6" "7" "8" "9" "COS" "LN" "LOG" "SIN" "TAN" "CLR" "DEL" "歐拉數" "圓周率" "小數點" "左括弧" "右括弧" "餘弦" "自然對數" "對數" "正弦" "正切" "加號" "除號" "階乘" "乘號" "指數" "平方根" "減號" "清除" "刪除" "等號"