{"id":4340,"date":"2021-11-17T12:22:12","date_gmt":"2021-11-17T05:22:12","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=4340"},"modified":"2021-11-17T12:22:14","modified_gmt":"2021-11-17T05:22:14","slug":"cach-tinh-nham-nhanh-va-hieu-qua","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/cach-tinh-nham-nhanh-va-hieu-qua\/","title":{"rendered":"C\u00e1ch t\u00ednh nh\u1ea9m nhanh v\u00e0 hi\u1ec7u qu\u1ea3"},"content":{"rendered":"\n

Ghi ch\u00fa: T\u00e0i li\u1ec7u tr\u00edch d\u1eabn<\/p>\n\n\n\n

Bi\u1ebft c\u00e1ch t\u00ednh nh\u1ea9m nhanh v\u00e0 ch\u00ednh x\u00e1c s\u1ebd gi\u00fap c\u00e1c em h\u1ecdc sinh<\/a> r\u1ea5t nhi\u1ec1u khi h\u1ecdc m\u00f4n To\u00e1n ho\u1eb7c nh\u1eefng l\u00fac c\u1ea7n t\u00ednh m\u1ed9t c\u00e1i g\u00ec \u0111\u00f3 m\u00e0 qu\u00ean mang m\u00e1y t\u00ednh theo b\u00ean m\u00ecnh. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t v\u00e0i \u201c m\u1eb9o \u201c v\u1ec1 c\u00e1ch t\u00ednh nh\u1ea9m th\u1eadt \u0111\u01a1n gi\u1ea3n m\u00e0 b\u1ea1n kh\u00f4ng th\u1ec3 t\u00ecm th\u1ea5y trong s\u00e1ch gi\u00e1o khoa.<\/p>\n\n\n\n

H\u00e3y c\u00f9ng v\u1edbi trung t\u00e2m Vietlearn h\u1ecdc th\u00eam 1 ki\u1ebfn th\u1ee9c m\u1edbi nh\u00e9!<\/p>\n\n\n\n

  1. B\u00ecnh ph\u01b0\u01a1ng s\u1ed1 c\u00f3 t\u1eadn c\u00f9ng l\u00e0 5 (ti\u1ec7n v\u1edbi s\u1ed1 c\u00f3 2 ch\u1eef s\u1ed1) :<\/li><\/ol>\n\n\n\n

    V\u00ed d\u1ee5: 65 x 65 = ?<\/p>\n\n\n\n

    5 x 5 = 25 => 65\u00d765=4225<\/p>\n\n\n\n

    6 x 7 = 42<\/p>\n\n\n\n

    C\u00e1ch gi\u1ea3i nh\u01b0 sau:<\/p>\n\n\n\n

    \u2013 X\u00e9t t\u00edch: 5\u00d75=25. Sau \u0111\u00f3 ghi s\u1ed1 n\u00e0y v\u00e0o t\u1eadn c\u00f9ng c\u1ee7a t\u00edch.<\/p>\n\n\n\n

    \u2013 Sau \u0111\u00f3, nh\u00e2n ch\u1eef s\u1ed1 h\u00e0ng ch\u1ee5c v\u1edbi ch\u1eef s\u1ed1 li\u1ec1n sau c\u1ee7a s\u1ed1 \u0111\u00f3 r\u1ed3i vi\u1ebft t\u00edch \u0111\u00f3 v\u00e0o tr\u01b0\u1edbc 25. Ta s\u1ebd c\u00f3 \u0111\u00e1p \u00e1n \u0111\u00fang. (xem v\u00ed d\u1ee5 \u1edf tr\u00ean)<\/p>\n\n\n\n

    1. \u00c1p d\u1ee5ng v\u1edbi ph\u00e9p t\u00ednh c\u00f3 s\u1ed1 h\u00e0ng ch\u1ee5c gi\u1ed1ng nhau, s\u1ed1 h\u00e0ng \u0111\u01a1n v\u1ecb c\u1ed9ng l\u1ea1i b\u1eb1ng 10:<\/li><\/ol>\n\n\n\n

      V\u00ed d\u1ee5: 94 x 96 = ?<\/p>\n\n\n\n

      Nh\u1ea9m: 4 x 6= 24 => 94\u00d796=9024<\/p>\n\n\n\n

      9 x 10 = 90<\/p>\n\n\n\n

      C\u00e1ch gi\u1ea3i nh\u01b0 sau:<\/p>\n\n\n\n

      \u2013 X\u00e9t t\u00edch c\u1ee7a 2 ch\u1eef s\u1ed1 h\u00e0ng \u0111\u01a1n v\u1ecb r\u1ed3i vi\u1ebft \u1edf cu\u1ed1i ph\u1ea7n \u0111\u00e1p \u00e1n t\u00edch.<\/p>\n\n\n\n

      \u2013 Sau \u0111\u00f3, nh\u00e2n ch\u1eef s\u1ed1 h\u00e0ng ch\u1ee5c v\u1edbi s\u1ed1 li\u1ec1n sau c\u1ee7a s\u1ed1 \u1ea5y r\u1ed3i \u0111\u1eb7t k\u1ebft qu\u1ea3 tr\u01b0\u1edbc t\u00edch c\u1ee7a 2 ch\u1eef s\u1ed1 h\u00e0ng \u0111\u01a1n v\u1ecb. Ta \u0111\u01b0\u1ee3c t\u00edch \u0111\u00fang.<\/p>\n\n\n\n

      1. B\u00ecnh ph\u01b0\u01a1ng nh\u1ea9m m\u1ed9t s\u1ed1 c\u00f3 2 ch\u1eef s\u1ed1 t\u00f9y \u00fd:<\/li><\/ol>\n\n\n\n

        X\u00e9t t\u00edch c\u1ee7a s\u1ed1 tr\u00f2n ch\u1ee5c g\u1ea7n nh\u1ea5t v\u1edbi s\u1ed1 tr\u00f2n ch\u1ee5c l\u1ea5y xu\u1ed1ng bao nhi\u00eau th\u00ec s\u1ed1 \u0111\u00f3 c\u00f4ng v\u00e0o b\u1ea5y nhi\u00eau, s\u1ed1 tr\u00f2n ch\u1ee5c m\u00e0 l\u1ea5y l\u00ean bao nhi\u00eau th\u00ec s\u1ed1 \u0111\u00f3 tr\u1eeb \u0111i b\u1ea5y nhi\u00eau r\u1ed3i c\u1ed9ng v\u1edbi t\u00edch l\u00e0 b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a s\u1ed1 \u0111\u01a1n v\u1ecb m\u00e0 s\u1ed1 tr\u00f2n ch\u1ee5c l\u1ea5y l\u00ean hay xu\u1ed1ng, ta \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 \u0111\u00fang.<\/p>\n\n\n\n

        V\u00ed d\u1ee5: 26 x 26 = ?<\/p>\n\n\n\n

        26 + 4 = 30 v\u00e0 26 \u2013 4 = 22<\/p>\n\n\n\n

        Nh\u1ea9m: 22 x 30 = 660<\/p>\n\n\n\n

        4 x 4 = 16<\/p>\n\n\n\n

        V\u1eady : 26 x 26 = 660 + 16 = 676<\/p>\n\n\n\n

        1. Nh\u00e2n nh\u1ea9m s\u1ed1 c\u00f3 2 ch\u1eef s\u1ed1 v\u1edbi s\u1ed1 c\u00f3 2 ch\u1eef s\u1ed1 \u0111\u1ed1i x\u1ee9ng nhau qua m\u1ed9t s\u1ed1 tr\u00f2n ch\u1ee5c:<\/li><\/ol>\n\n\n\n

          V\u00ed d\u1ee5: 71 x 89 = ?<\/p>\n\n\n\n

          Nh\u1ea9m: 80 x 80 = 6400 \uf0e8 71\u00d789= 6400-81= 6319<\/p>\n\n\n\n

          9 x 9 = 81<\/p>\n\n\n\n

          C\u00e1ch l\u00e0m nh\u01b0 sau:<\/p>\n\n\n\n

          \u2013 X\u00e9t b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a s\u1ed1 tr\u00f2n ch\u1ee5c g\u1ea7n nh\u1ea5t gi\u1eefa 2 s\u1ed1 r\u1ed3i tr\u1eeb \u0111i b\u00ecnh ph\u01b0\u01a1ng s\u1ed1 \u0111\u01a1n v\u1ecb c\u1ee7a th\u1eeba s\u1ed1 b\u1ecb gi\u1ea3m \u0111i hay t\u0103ng l\u00ean \u0111\u1ebfn s\u1ed1 tr\u00f2n ch\u1ee5c. Ta s\u1ebd c\u00f3 k\u1ebft qu\u1ea3 \u0111\u00fang.<\/p>\n\n\n\n

          Tr\u00ean \u0111\u00e2y l\u00e0 4 c\u00e1ch t\u00ednh nh\u1ea9m ph\u1ed5 bi\u1ebfn nh\u1ea5t, khi l\u00e0m n\u00f3 m\u1ed9t v\u00e0i l\u1ea7n th\u00ec c\u00e1c em s\u1ebd quen v\u00e0 t\u00ednh to\u00e1n nh\u1ea9m th\u1eadt nhanh. Ch\u1eb3ng c\u1ea7n ph\u1ea3i t\u00ednh b\u1eb1ng m\u00e1y t\u00ednh n\u1eefa, c\u00e1i g\u00ec nh\u1ea9m \u0111\u01b0\u1ee3c th\u00ec m\u00ecnh c\u1ee9 nh\u1ea9m v\u00ec n\u00f3 s\u1ebd ti\u1ebft ki\u1ec7m th\u1eddi gian cho c\u00e1c em. Kh\u00f4ng nh\u1eefng th\u1ebf, n\u00f3 c\u00f2n th\u1ec3 hi\u1ec7n \u0111\u1eb3ng c\u1ea5p c\u1ee7a m\u00ecnh n\u1eefa nh\u00e9!<\/p>\n\n\n\n

          N\u1ebfu c\u00f3 \u0111i\u1ec1u g\u00ec kh\u00f3 kh\u0103n trong vi\u00eac h\u1ecdc th\u00ec c\u00e1c em h\u00e3y comment \u0111\u1ec3 \u0111\u01b0\u1ee3c trung t\u00e2m gi\u1ea3i \u0111\u00e1p nh\u00e9. H\u00e3y like v\u00e0 share b\u00e0i vi\u1ebft nha c\u00e1c em.<\/p>\n\n\n\n

          Ch\u00fac c\u00e1c em h\u1ecdc th\u1eadt t\u1ed1t!<\/p>\n\n\n\n

          <\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"

          Ghi ch\u00fa: T\u00e0i li\u1ec7u tr\u00edch d\u1eabn Bi\u1ebft c\u00e1ch t\u00ednh nh\u1ea9m nhanh v\u00e0 ch\u00ednh x\u00e1c s\u1ebd gi\u00fap c\u00e1c em h\u1ecdc sinh r\u1ea5t nhi\u1ec1u khi h\u1ecdc m\u00f4n To\u00e1n ho\u1eb7c nh\u1eefng l\u00fac c\u1ea7n t\u00ednh m\u1ed9t c\u00e1i g\u00ec \u0111\u00f3 m\u00e0 qu\u00ean mang m\u00e1y t\u00ednh theo b\u00ean m\u00ecnh. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t v\u00e0i \u201c m\u1eb9o \u201c v\u1ec1 c\u00e1ch t\u00ednh nh\u1ea9m […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[1],"tags":[],"class_list":["post-4340","post","type-post","status-publish","format-standard","hentry","category-general"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/4340","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=4340"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/4340\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=4340"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=4340"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=4340"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}