{"id":25464,"date":"2021-12-24T16:50:47","date_gmt":"2021-12-24T09:50:47","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=25464"},"modified":"2021-12-24T16:50:48","modified_gmt":"2021-12-24T09:50:48","slug":"bai-so-5-do-vui-luyen-tri-thong-minh","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/bai-so-5-do-vui-luyen-tri-thong-minh\/","title":{"rendered":"B\u00c0I S\u1ed0 5 – \u0110\u1ed1 vui luy\u1ec7n tr\u00ed th\u00f4ng minh"},"content":{"rendered":"

<\/a>C\u00c2U 1:<\/h3>\n

B\u1ea1n c\u00f3 th\u1ec3 \u0111i\u1ec1n s\u1ed1 m\u1ea5y v\u00e0o d\u1ea5u? \u0110\u1ec3 h\u1ee3p l\u00f4gic nh\u1ea5t?<\/p>\n

\"12.jpg\"<\/p>\n

<\/a>C\u00c2U 2:<\/h3>\n

B\u1ea1n c\u00f3 th\u1ec3 c\u1eaft m\u1ed9t t\u1edd gi\u1ea5y h\u00ecnh ch\u1eef nh\u1eadt c\u00f3 chi\u1ec1u d\u00e0i 10cm v\u00e0 chi\u1ec1u r\u1ed9ng 4cm th\u00e0nh b\u1ed1n m\u1ea3nh v\u00e0 gh\u00e9p b\u1ed1n m\u1ea3nh n\u00e0y (kh\u00f4ng ch\u1ed3ng l\u00ean nhau) \u0111\u1ec3 c\u00f3 m\u1ed9t h\u00ecnh vu\u00f4ng \u0111\u01b0\u1ee3c kh\u00f4ng?<\/p>\n

<\/a>C\u00c2U 3:<\/h3>\n

C\u00f3 m\u1ed9t c\u00f4ng ch\u00faa c\u1ea5m cung, s\u1ed1ng trong t\u00f2a l\u00e2u \u0111\u00e0i c\u00f3 t\u1ea7ng tr\u1ec7t v\u00e0 4 t\u1ea7ng l\u1ea7u g\u1ed3m 31 ph\u00f2ng. S\u1ed1 ph\u00f2ng \u1edf t\u1ea7ng d\u01b0\u1edbi \u00edt h\u01a1n s\u1ed1 ph\u00f2ng \u1edf t\u1ea7ng tr\u00ean, s\u1ed1 ph\u00f2ng \u1edf t\u1ea7ng 4 g\u1ea5p 3 l\u1ea7n s\u1ed1 ph\u00f2ng \u1edf t\u1ea7ng tr\u1ec7t. H\u1ecfi t\u1ea7ng 3 c\u1ee7a c\u00f4ng ch\u00faa c\u00f3 bao nhi\u00eau ph\u00f2ng.<\/p>\n

<\/a>C\u00c2U 4:<\/h3>\n

(\u0110\u1ed1 m\u1eb9o):<\/p>\n

Con cua 8 c\u1eb3ng 2 c\u00e0ng h\u1ecfi b\u00f2 m\u1ea5y ch\u00e2n?<\/p>\n

<\/a>C\u00c2U 5:<\/h3>\n

\u0110\u1ed1 c\u00e1c b\u1ea1n l\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 c\u00f3 th\u1ec3 \u0111\u1ebfm \u0111\u00e0n ch\u00f3 nhanh nh\u1ea5t? (\u0111\u00e0n ch\u00f3 c\u00f3 kho\u1ea3ng 10 con).<\/p>\n

H\u01af\u1edaNG D\u1eaaN – B\u00c0I GI\u1ea2I – \u0110\u00c1P S\u1ed0<\/h1>\n

<\/a>B\u00c0I S\u1ed0 5<\/h2>\n

<\/a>C\u00c2U 1:<\/h3>\n

\u0110\u00e1p s\u1ed1:<\/p>\n

\u0110i\u1ec1n s\u1ed1 2 v\u00e0o d\u1ea5u ch\u1ea5m h\u1ecfi.<\/p>\n

<\/a>C\u00c2U 2:<\/h3>\n

B\u00e0i gi\u1ea3i:<\/p>\n

Ta chia t\u1edd gi\u1ea5y th\u00e0nh 40 \u00f4 vu\u00f4ng nh\u1ecf c\u1ea1nh l\u00e0 1 cm (ho\u1eb7c 10 \u00f4 vu\u00f4ng c\u1ea1nh 2cm). Ta c\u1eaft t\u1edd gi\u1ea5y theo \u0111\u01b0\u1eddng kh\u00f4ng li\u1ec1n n\u00e9t, ta \u0111\u01b0\u1ee3c b\u1ed1n m\u1ea3nh: 1, 2, 3, 4 v\u00e0 gh\u00e9p l\u1ea1i nh\u01b0 h\u00ecnh d\u01b0\u1edbi ta \u0111\u01b0\u1ee3c m\u1ed9t h\u00ecnh vu\u00f4ng m\u1edbi.<\/p>\n

\"106.jpg\"<\/p>\n

<\/a>C\u00c2U 3:<\/h3>\n

B\u00e0i gi\u1ea3i<\/p>\n

N\u1ebfu g\u1ecdi s\u1ed1 ph\u00f2ng \u1edf t\u1ea7ng tr\u1ec7t l\u00e0 1 ph\u1ea7n th\u00ec s\u1ed1 ph\u00f2ng \u1edf t\u1ea7ng 4 l\u00e0 3 ph\u1ea7n, do \u0111\u00f3 s\u1ed1 ph\u00f2ng \u1edf c\u1ea3 5 t\u1ea7ng \u00edt nh\u1ea5t l\u00e0<\/p>\n

1 + 1+ 1+ 1 + 3 = 7 (ph\u1ea7n)<\/p>\n

V\u00ec 31 : 7 = 4 (d\u01b0 3)<\/p>\n

N\u00ean s\u1ed1 ph\u00f2ng \u1edf t\u1ea7ng tr\u1ec7t nhi\u1ec1u nh\u1ea5t ch\u1ec9 l\u00e0 4 ph\u00f2ng. Ta l\u1ea7n l\u01b0\u1ee3t th\u1eed:<\/p>\n

a. N\u1ebfu t\u1ea7ng tr\u1ec7t c\u00f3 1 ph\u00f2ng th\u00ec t\u1ea7ng 4 c\u00f3 3 ph\u00f2ng. Gi\u1eefa 1 v\u00e0 3 ch\u1ec9 c\u00f3 s\u1ed1 2 n\u00ean \u0111i\u1ec1u n\u00e0y kh\u00f4ng \u0111\u00fang v\u1edbi \u0111\u1ea7u b\u00e0i (v\u00ec \u1edf gi\u1eefa t\u1ea7ng tr\u1ec7t v\u00e0 t\u1ea7ng 4 c\u00f3 t\u1edbi 3 t\u1ea7ng)<\/p>\n

b. N\u1ebfu t\u1ea7ng tr\u1ec7t c\u00f3 2 ph\u00f2ng th\u00ec t\u1ea7ng 4 c\u00f3 6 ph\u00f2ng. Gi\u1eefa s\u1ed1 2 v\u00e0 s\u1ed1 6 c\u00f3 3 s\u1ed1 3, 4, 5. Ta c\u00f3 2 + 3 + 4 + 5 + 6 = 20 (ph\u00f2ng).<\/p>\n

\u0110i\u1ec1u n\u00e0y kh\u00f4ng \u0111\u00fang v\u1edbi \u0111\u1ea7u b\u00e0i v\u00ec ch\u01b0a \u0111\u1ee7 31 ph\u00f2ng.<\/p>\n

C. N\u1ebfu t\u1ea7ng tr\u1ec7t c\u00f3 3 ph\u00f2ng th\u00ec t\u1ea7ng 4 c\u00f3 9 ph\u00f2ng. Gi\u1eefa s\u1ed1 3 v\u00e0 s\u1ed1 9 c\u00f3 5 s\u1ed1 4,5,6,7,8.<\/p>\n

V\u00ec: 31 \u2013 (3 + 9) = 19<\/p>\n

N\u00ean ta th\u1ea5y c\u00f3 hai tr\u01b0\u1eddng h\u1ee3p l\u00e0:<\/p>\n

4 + 7 + 8 = 19<\/p>\n

v\u00e0 5 + 6 + 8 = 19<\/p>\n

V\u1eady ta c\u00f3:<\/p>\n

3 + 4 + 7 + 8 + 9 = 31
\n3 + 5 + 6 + 8 + 9 = 31<\/p>\n

Trong c\u1ea3 hai tr\u01b0\u1eddng h\u1ee3p th\u00ec s\u1ed1 ph\u00f2ng \u1edf t\u1ea7ng 3 \u0111\u1ec1u l\u00e0 8, v\u1eady t\u1ea7ng 3 c\u00f3 8 ph\u00f2ng.<\/p>\n

<\/a>C\u00c2U 4:<\/h3>\n

H\u1ecfi b\u00f2 m\u1ea5y ch\u00e2n c\u00f3 ngh\u0129a l\u00e0 h\u1ecfi con b\u00f2 c\u00f3 m\u1ea5y ch\u00e2n? k\u1ebft qu\u1ea3 con b\u00f2 t\u1ea5t nhi\u00ean c\u00f3 4 ch\u00e2n.<\/p>\n

<\/a>C\u00c2U 5:<\/h3>\n

Trong c\u00e2u h\u1ecfi \u0111\u00e3 c\u00f3 c\u00e2u tr\u1ea3 l\u1eddi: c\u00f3 10 con.<\/p>\n","protected":false},"excerpt":{"rendered":"

C\u00c2U 1: B\u1ea1n c\u00f3 th\u1ec3 \u0111i\u1ec1n s\u1ed1 m\u1ea5y v\u00e0o d\u1ea5u? \u0110\u1ec3 h\u1ee3p l\u00f4gic nh\u1ea5t? C\u00c2U 2: B\u1ea1n c\u00f3 th\u1ec3 c\u1eaft m\u1ed9t t\u1edd gi\u1ea5y h\u00ecnh ch\u1eef nh\u1eadt c\u00f3 chi\u1ec1u d\u00e0i 10cm v\u00e0 chi\u1ec1u r\u1ed9ng 4cm th\u00e0nh b\u1ed1n m\u1ea3nh v\u00e0 gh\u00e9p b\u1ed1n m\u1ea3nh n\u00e0y (kh\u00f4ng ch\u1ed3ng l\u00ean nhau) \u0111\u1ec3 c\u00f3 m\u1ed9t h\u00ecnh vu\u00f4ng \u0111\u01b0\u1ee3c kh\u00f4ng? C\u00c2U 3: […]<\/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":[47],"tags":[],"class_list":["post-25464","post","type-post","status-publish","format-standard","hentry","category-do-vui"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25464","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=25464"}],"version-history":[{"count":1,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25464\/revisions"}],"predecessor-version":[{"id":25467,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25464\/revisions\/25467"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=25464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=25464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=25464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}