{"id":2708,"date":"2026-10-06T19:39:09","date_gmt":"2026-10-06T19:39:09","guid":{"rendered":"https:\/\/www.jrebsen.dk\/?post_type=aktivitet&#038;p=2708"},"modified":"2026-10-06T19:41:15","modified_gmt":"2026-10-06T19:41:15","slug":"primtal","status":"publish","type":"aktivitet","link":"https:\/\/www.jrebsen.dk\/?aktivitet=primtal","title":{"rendered":"Primtal"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">Introopgaver<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00e6lg en opgave og skriv besvarelsen p\u00e5 et stykke papir<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>1. Find primtallene<\/strong><br>Hvilke af disse tal er primtal?<br><strong>7 \u00b7 9 \u00b7 11 \u00b7 15 \u00b7 17 \u00b7 21 \u00b7 23 \u00b7 27 \u00b7 29<\/strong><br>Forklar, hvordan du afg\u00f8r, om et tal er et primtal.<br><\/td><td><strong>2. Find fejlen<\/strong><br>En elev siger:<br><strong>51 er et primtal, fordi det ikke kan deles med 2, 4, 5 eller 10.<\/strong><br>Har eleven ret? Hvis ikke, find en divisor og forklar, hvorfor 51 ikke er et primtal.<\/td><\/tr><tr><td><strong>3. Byg tal af primtal<\/strong><br>Skriv <strong>84<\/strong> som et produkt, hvor alle faktorer er primtal.<br>Eksempel: 30 = 2 \u00b7 3 \u00b7 5.<\/td><td><strong>4. Unders\u00f8g et m\u00f8nster<\/strong><br>Find to primtal, der har en forskel p\u00e5 <strong>2<\/strong>.<br>Find s\u00e5 mange s\u00e5danne par som muligt mellem <strong>1 og 100<\/strong>.<br><strong>Ekstra:<\/strong> Hvad kaldes s\u00e5danne par af primtal?<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Hvad er et Primtal <\/h3>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Et primtal er et tal st\u00f8rre end 1, der kun kan deles med 1 og sig selv.<\/strong> <\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Eksempler:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>2<\/strong> \u2192 kan kun deles med 1 og 2 \u2192 primtal<\/li>\n\n\n\n<li><strong>5<\/strong> \u2192 kan kun deles med 1 og 5 \u2192 primtal<\/li>\n\n\n\n<li><strong>6<\/strong> \u2192 kan deles med 1, 2, 3 og 6 \u2192 <strong>ikke<\/strong> primtal<\/li>\n\n\n\n<li><strong>7<\/strong> \u2192 kan kun deles med 1 og 7 \u2192 primtal<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Der er 25 primtal mellem 1 og 100:<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">SkoleDu.dk<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>KonteXt+9 <\/strong>\n<ul class=\"wp-block-list\">\n<li>S. 38 &#8216; Ud med matematikken&#8217;<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Problem- og f\u00e6rdighedsregning<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>FP9 Matematik med hj\u00e6lpemidler december 2023<\/li>\n\n\n\n<li>FP9 Matematik uden hj\u00e6lpemidler december 2023<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>&#8216;Potenser og r\u00f8dder&#8217;<\/strong>\n<ul class=\"wp-block-list\">\n<li>Link: <a href=\"https:\/\/app.skoledu.dk\/aflevering\/1005\">https:\/\/app.skoledu.dk\/aflevering\/1005<\/a><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>&#8216;<strong>Br\u00f8ker 1&#8242;<\/strong>\n<ul class=\"wp-block-list\">\n<li>Link: <a href=\"https:\/\/app.skoledu.dk\/aflevering\/957\">https:\/\/app.skoledu.dk\/aflevering\/957<\/a><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Introopgaver V\u00e6lg en opgave og skriv besvarelsen p\u00e5 et stykke papir 1. Find primtalleneHvilke af disse tal er primtal?7 \u00b7 9 \u00b7 11 \u00b7 15 \u00b7 17 \u00b7 21 \u00b7 23 \u00b7 27 \u00b7 29Forklar, hvordan du afg\u00f8r, om et tal er et primtal. 2. Find fejlenEn elev siger:51 er et primtal, fordi det ikke [&hellip;]<\/p>\n","protected":false},"featured_media":0,"menu_order":0,"template":"","meta":[],"categories":[],"tags":[],"aktivitetstype":[],"elementrolle":[],"fag":[90],"fagomraade":[],"produkt":[],"class_list":["post-2708","aktivitet","type-aktivitet","status-publish","hentry","fag-matematik"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=\/wp\/v2\/aktivitet\/2708","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=\/wp\/v2\/aktivitet"}],"about":[{"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=\/wp\/v2\/types\/aktivitet"}],"wp:attachment":[{"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2708"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2708"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2708"},{"taxonomy":"aktivitetstype","embeddable":true,"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Faktivitetstype&post=2708"},{"taxonomy":"elementrolle","embeddable":true,"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Felementrolle&post=2708"},{"taxonomy":"fag","embeddable":true,"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Ffag&post=2708"},{"taxonomy":"fagomraade","embeddable":true,"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Ffagomraade&post=2708"},{"taxonomy":"produkt","embeddable":true,"href":"https:\/\/www.jrebsen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fprodukt&post=2708"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}