{"id":51311,"date":"2026-01-31T15:45:31","date_gmt":"2026-01-31T15:45:31","guid":{"rendered":"https:\/\/www.oracletutoring.ca\/blog\/?p=51311"},"modified":"2026-01-31T15:45:33","modified_gmt":"2026-01-31T15:45:33","slug":"calculator-usage-fraction-format-on-the-casio-fx-991es-plus-c","status":"publish","type":"post","link":"https:\/\/www.oracletutoring.ca\/blog\/calculator-usage-fraction-format-on-the-casio-fx-991es-plus-c\/","title":{"rendered":"Calculator usage: fraction format on the Casio fx-991ES PLUS C"},"content":{"rendered":"\n<h2>Tutoring math, one notices features of calculators. The tutor mentions a way to set the default format of fractions to improper on the Casio fx-991ES PLUS C.<\/h2>\n<p>\nThe following is according to my understanding.<\/p>\n<p>\nFor background on mixed numerals and improper fractions, one might look <a href=\"https:\/\/www.oracletutoring.ca\/blog\/math-mixed-numerals-and-improper-fractions\/\">to my post from October 21, 2013.<\/a> The basic idea is that 21\/5 is an improper fraction, while 4<sup>1<\/sup>\/<sub>5<\/sub> is the same value as a mixed numeral.<\/p>\n<p>\nIn everyday life, people tend to use mixed numerals more, such as 2<sup>1<\/sup>\/<sub>2<\/sub> cups of flour. Yet, in math past grade 9, improper fractions are used more: 5\/2 cups of flour. The reason is that computations tend to be easier from the improper fraction form, especially mixed computations.<\/p>\n<p>\nA fraction means the top divided by the bottom: 10\/6 means &#8220;ten divided by 6.&#8221; On the Casio fx-991ES PLUS C, if one keys 10&divide;6, one might likely get the mixed numeral form, 1<sup>2<\/sup>\/<sub>3<\/sub>. Then, one can key Shift S<=>D (the S<=>D key is middle right, next to M+, on the model I&#8217;m using) to get 5\/3, which is improper form. 10\/6 = 5\/3: the calculator has reduced it.<\/p>\n<p>\nOne might get tired of always having to convert the mixed numeral to the improper fraction. In such a case one can set the calculator so it defaults to improper fraction form. It&#8217;s in the SET UP menu. The key sequence is Shift, then Mode, then Down Arrow (bottom of the round key below the display), then 2.<\/p>\n<p>Neat, eh?<\/p>\n<p>\nSource:<\/p>\n<p><a href=\"https:\/\/www.casio.com\/content\/dam\/casio\/global\/support\/manuals\/calculators\/pdf\/004-en\/f\/fx-115ESPLUS_991ESPLUSC_EN.pdf\">casio.com: fx-991ES PLUS C User&#8217;s Guide<\/a><\/p>\nJack of <a href=\"https:\/\/www.oracletutoring.ca\">Oracle Tutoring by Jack and Diane,<\/a> Campbell River, BC.  \n","protected":false},"excerpt":{"rendered":"<p>Tutoring math, one notices features of calculators. The tutor mentions a way to set the default format of fractions to improper on the Casio fx-991ES PLUS C. The following is according to my understanding. For background on mixed numerals and &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"more-link\" href=\"https:\/\/www.oracletutoring.ca\/blog\/calculator-usage-fraction-format-on-the-casio-fx-991es-plus-c\/\"> <span class=\"screen-reader-text\">Calculator usage: fraction format on the Casio fx-991ES PLUS C<\/span> Read More &raquo;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[90],"tags":[295,4006,4002,4003,4005,4004],"class_list":["post-51311","post","type-post","status-publish","format-standard","hentry","category-calculator-usage","tag-casio-fx-991es","tag-default-settings","tag-improper-fraction","tag-mixed-numeral","tag-setup-menu","tag-what-does-a-fraction-mean"],"_links":{"self":[{"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/posts\/51311","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/comments?post=51311"}],"version-history":[{"count":4,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/posts\/51311\/revisions"}],"predecessor-version":[{"id":51315,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/posts\/51311\/revisions\/51315"}],"wp:attachment":[{"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/media?parent=51311"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/categories?post=51311"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/tags?post=51311"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}