{"id":8866,"date":"2021-11-08T14:00:00","date_gmt":"2021-11-08T13:00:00","guid":{"rendered":"http:\/\/samuserensemble.fr\/?p=8866"},"modified":"2021-10-31T12:11:57","modified_gmt":"2021-10-31T11:11:57","slug":"calcul-mental-les-carres-a-toute-vitesse","status":"publish","type":"post","link":"http:\/\/samuserensemble.fr\/?p=8866","title":{"rendered":"Calcul mental : les carr\u00e9s \u00e0 toute vitesse"},"content":{"rendered":"\n<p>Voici une astuce qui nous a bien amus\u00e9s : nous sommes d\u00e9sormais capables de calculer le carr\u00e9 d&rsquo;un nombre plus vite que notre interlocuteur disposant d&rsquo;une calculatrice&#8230; Ok, relativisons un peu, il ne s&rsquo;agit que de nombres \u00e0 deux chiffres, et encore si le dernier est 5, mais quand m\u00eame !<\/p>\n\n\n\n<p>Si vous nous demandez quel est le carr\u00e9 de 75, nous pouvons vous r\u00e9pondre 5625 avant que vous n&rsquo;ayez obtenu le r\u00e9sultat sur la calculatrice. Comment ? Il y a bien s\u00fbr une astuce.<\/p>\n\n\n\n<p>Pour commencer, le carr\u00e9 de tous les nombres \u00e0 deux chiffres se finissant par 5 va se terminer par 25. Vous avez donc d\u00e9j\u00e0 les deux derniers chiffres, sans aucune r\u00e9flexion.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"336\" src=\"http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-1-1024x336.jpg\" alt=\"M\u00e9thode pour le calcul rapide 1\" class=\"wp-image-8890\" srcset=\"http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-1-1024x336.jpg 1024w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-1-300x98.jpg 300w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-1-768x252.jpg 768w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-1-450x147.jpg 450w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-1-850x278.jpg 850w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-1-1000x328.jpg 1000w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-1.jpg 1230w\" sizes=\"(max-width: 739px) 94vw, (max-width: 969px) 88vw, (max-width: 1199px) 860px, 850px\" \/><\/figure>\n\n\n\n<p>Ensuite, il faut s&rsquo;occuper de la dizaine. C&rsquo;est le seul calcul \u00e0 faire et il n&rsquo;est pas tr\u00e8s difficile. Prenez le chiffre de la dizaine et multipliez-le par le chiffre qui vient tout de suite au-dessus.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"316\" src=\"http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-2-1024x316.jpg\" alt=\"M\u00e9thode pour le calcul rapide 2\" class=\"wp-image-8891\" srcset=\"http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-2-1024x316.jpg 1024w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-2-300x93.jpg 300w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-2-768x237.jpg 768w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-2-450x139.jpg 450w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-2-850x262.jpg 850w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-2-1000x309.jpg 1000w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-2.jpg 1231w\" sizes=\"(max-width: 739px) 94vw, (max-width: 969px) 88vw, (max-width: 1199px) 860px, 850px\" \/><\/figure>\n\n\n\n<p>Prenons un exemple : quel est le carr\u00e9 de 85 ? Forc\u00e9ment, cela va se terminer par 25.<\/p>\n\n\n\n<p>85 commence par un 8 et 9 vient tout de suite au-dessus de 8. On fait donc 8 x 9 et on obtient 72.<\/p>\n\n\n\n<p>85 au carr\u00e9 fait donc 7225. Vous pouvez v\u00e9rifier !<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"481\" src=\"http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-3-1024x481.jpg\" alt=\"M\u00e9thode pour le calcul rapide 3\" class=\"wp-image-8892\" srcset=\"http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-3-1024x481.jpg 1024w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-3-300x141.jpg 300w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-3-768x361.jpg 768w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-3-450x211.jpg 450w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-3-850x399.jpg 850w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-3-1000x470.jpg 1000w, http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/Carres-3.jpg 1230w\" sizes=\"(max-width: 739px) 94vw, (max-width: 969px) 88vw, (max-width: 1199px) 860px, 850px\" \/><\/figure>\n\n\n\n<p>Outre qu&rsquo;il est \u00e9tonnamment satisfaisant de faire vite et facilement une op\u00e9ration qui semble complexe, c&rsquo;est surtout un petit tour \u00e0 faire \u00e0 ses amis pour leur faire croire qu&rsquo;on a aval\u00e9 la calculatrice. Il suffit de dire \u00e0 voix haute, \u00ab\u00a0Alors, le carr\u00e9 de X5 est&#8230;\u00a0\u00bb et de faire en m\u00eame temps le petit calcul pour la dizaine, et cela semble une r\u00e9ponse quasiment instantan\u00e9e. Surprenant !<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Voici une astuce qui nous a bien amus\u00e9s : nous sommes d\u00e9sormais capables de calculer le carr\u00e9 d&rsquo;un [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":8889,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[699],"tags":[103,413],"class_list":["post-8866","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-apprendre-en-samusant","tag-calcul","tag-mathematiques"],"aioseo_notices":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"http:\/\/samuserensemble.fr\/wp-content\/uploads\/2021\/10\/mathematics-936697_1920.jpg","_links":{"self":[{"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=\/wp\/v2\/posts\/8866","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8866"}],"version-history":[{"count":6,"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=\/wp\/v2\/posts\/8866\/revisions"}],"predecessor-version":[{"id":8897,"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=\/wp\/v2\/posts\/8866\/revisions\/8897"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=\/wp\/v2\/media\/8889"}],"wp:attachment":[{"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8866"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8866"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/samuserensemble.fr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8866"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}