{"id":25638,"date":"2021-12-24T17:35:49","date_gmt":"2021-12-24T10:35:49","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=25638"},"modified":"2021-12-24T17:35:50","modified_gmt":"2021-12-24T10:35:50","slug":"bai-so-38-do-vui-luyen-tri-thong-minh","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/bai-so-38-do-vui-luyen-tri-thong-minh\/","title":{"rendered":"B\u00c0I S\u1ed0 38 – \u0110\u1ed1 vui luy\u1ec7n tr\u00ed th\u00f4ng minh"},"content":{"rendered":"

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

H\u00ecnh n\u00e0o kh\u00e1c lo\u1ea1i:<\/p>\n

\"81.jpg\"<\/p>\n

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

C\u00f3 3 c\u00e1i th\u00f9ng:<\/p>\n

– C\u00e1i th\u1ee9 1 \u0111\u1ef1ng 16 l\u00edt n\u01b0\u1edbc<\/p>\n

– C\u00e1i th\u1ee9 2 c\u00f3 dung t\u00edch 11 l\u00edt (kh\u00f4ng ch\u1ee9a n\u01b0\u1edbc)<\/p>\n

– C\u00e1i th\u1ee9 3 c\u00f3 dung t\u00edch 6 l\u00edt c\u0169ng kh\u00f4ng ch\u1ee9a n\u01b0\u1edbc<\/p>\n

H\u1ecfi b\u1ea1n ph\u1ea3i \u0111\u1ed5 nh\u01b0 th\u1ebf n\u00e0o \u0111\u1ec3 th\u00f9ng th\u1ee9 1 v\u00e0 th\u1ee9 2 c\u00f3 s\u1ed1 l\u00edt n\u01b0\u1edbc b\u1eb1ng nhau? (\u0110\u1ec1u b\u1eb1ng 8 l\u00edt)<\/p>\n

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

B\u1ea1n c\u00f3 m\u1ed9t s\u1ed1 s\u1ee3i d\u00e2y ch\u00e1y ch\u1eadm d\u00f9ng l\u00e0m ng\u00f2i ph\u00e1o. M\u1ed7i s\u1ee3i d\u00e2y ch\u00e1y t\u1eeb \u0111\u1ea7u \u0111\u1ebfn cu\u1ed1i m\u1ea5t 1 gi\u1edd nh\u01b0ng ch\u00e1y kh\u00f4ng \u0111\u01b0\u1ee3c. N\u1eeda s\u1ee3i \u0111\u1ea7u ch\u00e1y v\u00e8o trong 10 ph\u00fat, n\u1eeda c\u00f2n l\u1ea1i ch\u00e1y trong 50 ph\u00fat. V\u1edbi s\u1ed1 d\u00e2y n\u00e0y, b\u1ea1n c\u00f3 th\u1ec3 \u0111o \u0111\u01b0\u1ee3c gi\u1edd kh\u00f4ng?<\/p>\n

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

C\u00f3 8 t\u1ea5m b\u00eca tr\u00ean \u0111\u00f3 m\u1ed7i t\u1ea5m \u0111\u01b0\u1ee3c ghi c\u00e1c con s\u1ed1 l\u1ea7n l\u01b0\u1ee3t l\u00e0: 1; 2; 3; 4; 5; 7; 8; 9. B\u1ea1n h\u00e3y chia 8 t\u1ea5m b\u00eca tr\u00ean th\u00e0nh hai nh\u00f3m sao cho t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 c\u1ee7a 2 nh\u00f3m b\u1eb1ng nhau?<\/p>\n

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

C\u00f3 5 \u0111o\u1ea1n x\u00edch, m\u1ed7i \u0111o\u1ea1n c\u00f3 3 m\u1eaft x\u00edch. H\u1ecfi ng\u01b0\u1eddi th\u1ee3 r\u00e8n c\u1ea7n th\u00e1o ra v\u00e0 gh\u00e9p \u00edt nh\u1ea5t bao nhi\u00eau \u0111o\u1ea1n m\u1eaft x\u00edch \u0111\u1ec3 \u0111\u01b0\u1ee3c 1 \u0111o\u1ea1n x\u00edch d\u00e0i li\u00ean t\u1ee5c. Tr\u00ecnh b\u00e0y c\u1ea3 c\u00e1ch c\u1eaft v\u00e0 gh\u00e9p?<\/p>\n

<\/a>C\u00c2U 6:<\/h3>\n

C\u00f3 100 \u0111\u1ed9i b\u00f3ng, ph\u1ea3i \u0111\u1ea5u \u00edt nh\u1ea5t bao nhi\u00eau tr\u1eadn \u0111\u1ec3 c\u00f3 \u0111\u1ed9i \u0111\u1ea1t gi\u1ea3i qu\u00e1n qu\u00e2n?<\/p>\n

<\/a>C\u00c2U 7:<\/h3>\n

\u0110\u1ed1 vui v\u1eeba h\u1ecdc v\u1eeba ch\u01a1i<\/p>\n

L\u00e0m theo 2 c\u00e1ch xin m\u1eddi b\u1ea1n ghi<\/p>\n

Thu\u1ed9c l\u00e0u quy t\u1eafc kh\u00f3 chi<\/p>\n

Tr\u00ecnh b\u00e0y r\u00f5 \u0111\u1eb9p c\u00f9ng thi \u0111ua t\u00e0i<\/p>\n

Th\u1eed xem ai gi\u1ecfi h\u01a1n ai<\/p>\n

A\/ ( 15 + 20) : 5 = ?<\/p>\n

B\/ ( 20 + 16) : 4 = ?<\/p>\n

C\/ ( 21 + 14) : 7 = ?<\/p>\n

D\/ ( 81 + 18 ) : 9 = ?<\/p>\n

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

<\/a>B\u00c0I S\u1ed0 38<\/h2>\n

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

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

H\u00ecnh C kh\u00e1c c\u00e1c h\u00ecnh c\u00f2n l\u1ea1i.<\/p>\n

\"177.jpg\"<\/p>\n

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

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

\u0110\u1ea7u ti\u00ean: L\u1ea5y th\u00f9ng 16 l\u00edt \u0111\u1ed5 cho \u0111\u1ea7y th\u00f9ng 6 l\u00edt, trong th\u00f9ng c\u00f2n 10 l\u00edt, s\u1ed1 n\u01b0\u1edbc 10 l\u00edt \u0111\u00f3 \u0111\u1ed5 h\u1ebft cho th\u00f9ng 11 l\u00edt.<\/p>\n

Ti\u1ebfp theo: L\u1ea5y th\u00f9ng 6 l\u00edt \u0111\u1ed5 h\u1ebft v\u00e0o th\u00f9ng 16 l\u00edt.<\/p>\n

Ti\u1ebfp theo: L\u1ea5y th\u00f9ng 11 l\u00edt (l\u00fac n\u00e0y ch\u1ee9a 10 l\u00edt) \u0111\u1ed5 sang th\u00f9ng 6 l\u00edt cho \u0111\u1ea7y, v\u1eady trong th\u00f9ng 11 l\u00edt l\u00fac n\u00e0y c\u00f2n 4 l\u00edt.<\/p>\n

Ti\u1ebfp theo \u0111\u1ed5 6 l\u00edt sang th\u00f9ng ch\u1ee9a 16 l\u00edt \u0111\u1ed5 4 l\u00edt \u1edf th\u00f9ng ch\u1ee9a 11 l\u00edt sang th\u00f9ng ch\u1ee9a 6 l\u00edt.<\/p>\n

V\u1eady th\u00f9ng 16 l\u00edt c\u00f2n 12 l\u00edt, th\u00f9ng 11 l\u00edt c\u00f2n 0 l\u00edt, th\u00f9ng 6 c\u00f2n 4 l\u00edt.<\/p>\n

L\u1ea5y th\u00f9ng 16 l\u00edt \u0111\u1ed5 \u0111\u1ea7y th\u00f9ng 11 l\u00edt \u2260 L\u1ea5y th\u00f9ng 11 l\u00edt \u0111\u1ed5 \u0111\u1ea7y th\u00f9ng 6 l\u00edt \u2260 th\u00f9ng 11 l\u00edt c\u00f2n 9 l\u00edt. \u0111\u1ed5 h\u1ebft th\u00f9ng 6 l\u00edt v\u00e0o th\u00f9ng 16 l\u00edt \u2260 11 l\u00edt (c\u00f3 9 l\u00edt) \u0111\u1ed5 \u0111\u1ea7y th\u00f9ng 6 l\u00edt \u2260 th\u00f9ng 11 l\u00edt c\u00f2n 3 l\u00edt.<\/p>\n

—> th\u00f9ng 16 l\u00edt c\u00f2n 7 l\u00edt.<\/p>\n

Th\u00f9ng 11 l\u00edt c\u00f2n 3l\u00edt.<\/p>\n

Th\u00f9ng 6 l\u00edt c\u00f2n 6l\u00edt.<\/p>\n

\u2260 \u0111\u1ed5 h\u1ebft th\u00f9ng 6 l\u00edt v\u00e0o th\u00f9ng 16 l\u00edt, r\u1ed3i \u0111\u1ed5 h\u1ebft th\u00f9ng 11 l\u00edt v\u00e0o th\u00f9ng 6 l\u00edt th\u00f9ng 6 l\u00edt c\u00f3 3 l\u00edt.<\/p>\n

\u0110\u1ed5 \u0111\u1ea7y th\u00f9ng 11 l\u00edt r\u1ed3i l\u1ea5y th\u00f9ng 11 l\u00edt \u0111\u1ed5 \u0111\u1ea7y th\u00f9ng 6 l\u00edt \u2260 th\u00f9ng 11 l\u00edt ch\u1ee9a 8 l\u00edt, gi\u1edd ch\u1ec9 c\u1ea7n \u0111\u1ed5 th\u00f9ng 6 l\u00edt v\u00e0o th\u00f9ng 16 l\u00edt \u2260 th\u00f9ng 16 l\u00edt ch\u1ee9a 8 l\u00edt.<\/p>\n

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

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

Ta \u0111\u1ed1t 2 s\u1ee3i d\u00e2y; m\u1ed9t s\u1ee3i \u0111\u1ed1t \u1edf c\u1ea3 2 \u0111\u1ea7u, c\u00f2n s\u1ee3i kia th\u00ec ch\u1ec9 \u0111\u1ed1t 1 \u0111\u1ea7u th\u00f4i.<\/p>\n

Khi s\u1ee3i th\u1ee9 nh\u1ea5t ch\u00e1y h\u1ebft, th\u00ec s\u1ee3i th\u1ee9 hai ch\u1ec9 m\u1edbi ch\u00e1y \u0111\u01b0\u1ee3c 30 ph\u00fat, c\u00f2n l\u1ea1i 30 ph\u00fat. Ti\u1ebfp theo ta \u0111\u1ed1t th\u00eam 1 \u0111\u1ea7u kia c\u1ee7a s\u1ee3i d\u00e2y c\u00f2n l\u1ea1i n\u1eefa, \u0111\u1ec3 ch\u00e1y h\u1ebft n\u00f3 m\u1ea5t th\u00eam 15 ph\u00fat n\u1eefa.<\/p>\n

V\u1eady ta \u0111o \u0111\u01b0\u1ee3c 45 ph\u00fat = 3\/4 gi\u1edd.<\/p>\n

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

\u0110\u00e2y l\u00e0 1 b\u00e0i to\u00e1n m\u1eb9o => ta s\u1ebd l\u1eadt ng\u01b0\u1ee3c s\u1ed1 9 => n\u00f3 tr\u1edf th\u00e0nh s\u1ed1 6 => 1+ 2 +… + 8 = 36 => m\u1ed7i nh\u00f3m c\u00f3 t\u1ed5ng l\u00e0 18<\/p>\n

V\u1eady nh\u00f3m 1 l\u00e0: 1, 4, 6, 7<\/p>\n

Nh\u00f3m 2 l\u00e0: 2, 8, 3, 5.<\/p>\n

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

Ba l\u1ea7n, th\u00e1o tung 1 \u0111o\u1ea1n x\u00edch ra, r\u1ed3i l\u1ea5y t\u1eebng m\u1eaft x\u00edch l\u00e0 “c\u1ea7u n\u1ed1i” nh\u1eefng \u0111o\u1ea1n x\u00edch c\u00f2n l\u1ea1i.<\/p>\n

<\/a>C\u00c2U 6:<\/h3>\n

\u0110\u00e1p s\u1ed1: 99 tr\u1eadn.<\/p>\n

<\/a>C\u00c2U 7:<\/h3>\n

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

A\/ (15 + 20) : 5 = ?<\/p>\n

C\u00e1ch 1:<\/p>\n

(15 + 20) : 5 = ?<\/p>\n

=> 35 : 5 = 7<\/p>\n

V\u1eady (15 + 20) : 5 = 7<\/p>\n

C\u00e1ch 2:<\/p>\n

(15 + 20) : 5 = ?<\/p>\n

=> (15 : 5) + (20 : 5) = ?<\/p>\n

=> 3 + 4 = ?<\/p>\n

=> 3 + 4 = 7<\/p>\n

V\u1eady (15 + 20) : 5 = 7<\/p>\n

B\/ (20 + 16) : 4 = ?<\/p>\n

C\u00e1ch 1:<\/p>\n

(20 + 16) : 4 = ?<\/p>\n

=> 36 : 4 = 9<\/p>\n

V\u1eady (20 + 16) : 4 = 9<\/p>\n

C\u00e1ch 2:<\/p>\n

(20 + 16) : 4 = ?<\/p>\n

=> (20 : 4) + (16 : 4) = ?<\/p>\n

=> 5 + 4 = ?<\/p>\n

=> 5 + 4 = 9<\/p>\n

V\u1eady (20 + 16) : 4 = 9<\/p>\n

C\/ (21 + 14) : 7 = ?<\/p>\n

C\u00e1ch 1:<\/p>\n

(21 + 14) : 7 = ?<\/p>\n

=> 35 : 7 = 5<\/p>\n

V\u1eady (21 + 14) : 7 = 5<\/p>\n

C\u00e1ch 2<\/p>\n

(21 + 14) : 7 = ?<\/p>\n

=> (21 : 7) + (14 : 7) = ?<\/p>\n

=> 3 + 2 = ?<\/p>\n

=> 3 + 2 = 5<\/p>\n

V\u1eady (21 + 14) : 7 = 5<\/p>\n

D\/ (81 + 18 ) : 9 = ?<\/p>\n

C\u00e1ch 1:<\/p>\n

(81 + 18) : 9 = ?<\/p>\n

=> 99 : 9 = 11<\/p>\n

V\u1eady (81 + 18) : 9 = 11<\/p>\n

C\u00e1ch 2:<\/p>\n

(81 + 18) : 9 = ?<\/p>\n

=> (81 : 9) + (18 : 9) = ?<\/p>\n

=> 9 + 2 = ?<\/p>\n

=> 9 + 2 = 11<\/p>\n

V\u1eady (81 + 18) : 9 = 11<\/p>\n","protected":false},"excerpt":{"rendered":"

C\u00c2U 1: H\u00ecnh n\u00e0o kh\u00e1c lo\u1ea1i: C\u00c2U 2: C\u00f3 3 c\u00e1i th\u00f9ng: – C\u00e1i th\u1ee9 1 \u0111\u1ef1ng 16 l\u00edt n\u01b0\u1edbc – C\u00e1i th\u1ee9 2 c\u00f3 dung t\u00edch 11 l\u00edt (kh\u00f4ng ch\u1ee9a n\u01b0\u1edbc) – C\u00e1i th\u1ee9 3 c\u00f3 dung t\u00edch 6 l\u00edt c\u0169ng kh\u00f4ng ch\u1ee9a n\u01b0\u1edbc H\u1ecfi b\u1ea1n ph\u1ea3i \u0111\u1ed5 nh\u01b0 th\u1ebf n\u00e0o \u0111\u1ec3 th\u00f9ng th\u1ee9 […]<\/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-25638","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\/25638","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=25638"}],"version-history":[{"count":1,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25638\/revisions"}],"predecessor-version":[{"id":25641,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25638\/revisions\/25641"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=25638"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=25638"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=25638"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}