{"id":680,"date":"2011-09-04T12:15:22","date_gmt":"2011-09-04T12:15:22","guid":{"rendered":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/?p=680"},"modified":"2011-09-04T12:15:22","modified_gmt":"2011-09-04T12:15:22","slug":"the-significance-of-rounding-and-significant-figures","status":"publish","type":"post","link":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/?p=680","title":{"rendered":"The significance of rounding and significant figures"},"content":{"rendered":"<p>I now find myself\u00a0chairing the production of\u00a0two new Open University\u00a0modules, so writing course materials ought to take priority over writing this blog. That&#8217;s a pity, because there&#8217;s so much assessment-related that I want to reflect on.<\/p>\n<p>As a compromise, I&#8217;ve decided to report a few\u00a0more of the things that I&#8217;m finding out from our analysis of student responses to \u00a0<a href=\"http:\/\/www3.open.ac.uk\/study\/undergraduate\/course\/s151.htm\">Maths for Science <\/a>e-assessment\u00a0questions (since it&#8217;s Maths for Science that I am deep in re-writing at the moment). Some of the findings reinforce what we already know, some are unexpected. However, in each case, if there are mistakes being made by a number of students then it behoves us to look carefully at our teaching in those areas.<\/p>\n<p>As an example &#8211; our students seem to be really bad at rounding &#8211; they will truncate 1.465 to 1.4 rather than rounding it to 1.5. I still don&#8217;t really know why this is, or whether it&#8217;s a common problem with students at conventional universities. However, when I looked carefully I realised that so far Maths for Science was concerned, one of the problems\u00a0was that\u00a0we didn&#8217;t explicitly\u00a0students how to round\u00a0(though we did teach rounding in the context of orders of magnitude). Oops! Hopefully the new edition of the book will do better.<\/p>\n<p>Our students are also really bad at quoting numbers to an appropriate number of significant figures. After more than 20 years of teaching OU students, this finding didn&#8217;t really surprise me &#8211; and it is reasonable that students will more readily quote an answer of 3.4 as being to two significant figures than they will 0.034 or 3.0. I&#8217;ve tried to improve our teaching of these points too, but I&#8217;m not optimistic as to my chances of success.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I now find myself\u00a0chairing the production of\u00a0two new Open University\u00a0modules, so writing course materials ought to take priority over writing this blog. That&#8217;s a pity, because there&#8217;s so much assessment-related that I want to reflect on. As a compromise, I&#8217;ve &hellip; <a href=\"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/?p=680\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[111,110],"tags":[369,368,161,372],"class_list":["post-680","post","type-post","status-publish","format-standard","hentry","category-mathematical-misunderstandings","category-question-analysis","tag-mathematical-misunderstandings","tag-question-analysis","tag-rounding","tag-significant-figures"],"_links":{"self":[{"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=\/wp\/v2\/posts\/680","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=680"}],"version-history":[{"count":1,"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=\/wp\/v2\/posts\/680\/revisions"}],"predecessor-version":[{"id":681,"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=\/wp\/v2\/posts\/680\/revisions\/681"}],"wp:attachment":[{"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=680"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=680"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.open.ac.uk\/blogs\/SallyJordan\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=680"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}