{"id":25429,"date":"2021-12-24T16:40:01","date_gmt":"2021-12-24T09:40:01","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=25429"},"modified":"2021-12-24T16:41:08","modified_gmt":"2021-12-24T09:41:08","slug":"25429","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/25429\/","title":{"rendered":"B\u00c0I S\u1ed0 1 – \u0110\u1ed1 vui luy\u1ec7n tr\u00ed th\u00f4ng minh"},"content":{"rendered":"

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

Cho d\u00e3y c\u00e1c s\u1ed1 ch\u1eb5n li\u00ean ti\u1ebfp: 2; 4; 6; 8; … ; 998; 1000.<\/p>\n

Sau khi \u0111i\u1ec1n th\u00eam c\u00e1c d\u1ea5u + ho\u1eb7c d\u1ea5u – v\u00e0o gi\u1eefa c\u00e1c s\u1ed1 theo \u00fd m\u00ecnh, b\u1ea1n B\u00ecnh th\u1ef1c hi\u1ec7n ph\u00e9p T\u00ednh \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0 2002; b\u1ea1n Minh th\u1ef1c hi\u1ec7n ph\u00e9p T\u00ednh \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0 2006. Ai T\u00ednh \u0111\u00fang?<\/p>\n

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

B\u1ea1n h\u00e3y chia t\u1ea5m b\u00eca b\u00ean d\u01b0\u1edbi th\u00e0nh 6 ph\u1ea7n gi\u1ed1ng h\u1ec7t nhau v\u1ec1 h\u00ecnh d\u1ea1ng v\u00e0 m\u1ed7i ph\u1ea7n c\u00f3 m\u1ed9t b\u00f4ng hoa.<\/p>\n

\"5.jpg\"<\/p>\n

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

Tang t\u1ea3ng l\u00fac tr\u1eddi m\u1edbi r\u1ea1ng \u0111\u00f4ng<\/p>\n

R\u1ee7 nhau \u0111i h\u00e1i m\u1ea5y qu\u1ea3 b\u00f4ng<\/p>\n

M\u1ed7i ng\u01b0\u1eddi 5 qu\u1ea3 th\u1eeba 5 qu\u1ea3<\/p>\n

M\u1ed7i ng\u01b0\u1eddi 6 qu\u1ea3 1 ng\u01b0\u1eddi kh\u00f4ng.<\/p>\n

H\u1ecfi c\u00f3 bao nhi\u00eau ng\u01b0\u1eddi, bao nhi\u00eau qu\u1ea3 b\u00f4ng?<\/p>\n

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

\u1ede m\u1ed9t v\u01b0\u01a1ng qu\u1ed1c n\u1ecd c\u00f3 1 n\u00e0ng c\u00f4ng ch\u00faa xinh \u0111\u1eb9p, n\u00ean c\u00f3 10 ch\u00e0ng trai kh\u00f4i ng\u00f4 tu\u1ea5n t\u00fa \u0111\u1ebfn xin c\u01b0\u1edbi n\u00e0ng c\u00f9ng l\u00fac. V\u00ec h\u1ecd \u0111\u1ec1u gi\u00e0u sang nh\u01b0 nhau n\u00ean vua cha m\u1edbi \u0111\u01b0a ra m\u1ed9t t\u00ecnh th\u1ebf sau:<\/p>\n

Vua \u0111\u01b0a c\u00f4ng ch\u00faa l\u00ean m\u1ed9t c\u00e1i th\u00e1p cao v\u00fat v\u00e0 b\u1ea3o r\u1eb1ng, n\u1ebfu ch\u00e0ng trai n\u00e0o tr\u1ea3 l\u1eddi cho vua bi\u1ebft c\u00f3 bao nhi\u00eau b\u1eadc thang d\u1eabn l\u00ean ch\u1ed7 c\u00f4ng ch\u00faa th\u00ec s\u1ebd cho c\u1eed h\u00e0nh h\u00f4n l\u1ec5 ngay. Vua cho c\u00e1c ch\u00e0ng trai bi\u1ebft m\u1ed9t v\u00e0i s\u1ed1 li\u1ec7u: s\u1ed1 b\u1eadc thang nhi\u1ec1u h\u01a1n 100 v\u00e0 \u00edt h\u01a1n 120. N\u1ebfu l\u00ednh canh b\u01b0\u1edbc m\u1ed9t l\u1ea7n 3 b\u1eadc s\u1ebd c\u00f2n th\u1eeba ra 1 b\u1eadc, n\u1ebfu b\u01b0\u1edbc m\u1ed9t l\u1ea7n 4 b\u1eadc s\u1ebd c\u00f2n th\u1eeba 2, n\u1ebfu b\u01b0\u1edbc 5 b\u1eadc s\u1ebd c\u00f2n th\u1eeba 3.<\/p>\n

V\u1eady s\u1ebd c\u00f3 bao nhi\u00eau b\u1eadc thang?<\/p>\n

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

<\/a>B\u00c0I S\u1ed0 1<\/h2>\n

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

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

T\u1eeb 2 \u0111\u1ebfn 1000 c\u00f3: (1000 – 2) : 2 + 1 = 500 (s\u1ed1 ch\u1eb5n).<\/p>\n

T\u1ed5ng c\u00e1c s\u1ed1 \u0111\u00f3: N = (1000 + 2) x 500 : 2 = 250500. S\u1ed1 n\u00e0y chia h\u1ebft cho 4.<\/p>\n

Khi thay + a th\u00e0nh – a th\u00ec N b\u1ecb gi\u1ea3m \u0111i a x 2 c\u0169ng l\u00e0 s\u1ed1 chia h\u1ebft cho 4. Do \u0111\u00f3 k\u1ebft qu\u1ea3 cu\u1ed1i c\u00f9ng ph\u1ea3i l\u00e0 s\u1ed1 chia h\u1ebft cho 4. B\u00ecnh t\u00ednh \u0111\u01b0\u1ee3c 2002, minh t\u00ednh \u0111\u01b0\u1ee3c 2006 \u0111\u1ec1u l\u00e0 s\u1ed1 kh\u00f4ng chia h\u1ebft cho 4. V\u1eady c\u1ea3 hai b\u1ea1n \u0111\u1ec1u t\u00ednh sai.<\/p>\n

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

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

Ta chia t\u1ea5m b\u00eca th\u00e0nh c\u00e1c \u00f4 vu\u00f4ng nh\u1ecf b\u1eb1ng nhau nh\u01b0 trong h\u00ecnh v\u1ebd sau:<\/p>\n

\"90_1.jpg\"<\/p>\n

Nh\u00ecn h\u00ecnh v\u1ebd ta th\u1ea5y t\u1ed5ng s\u1ed1 \u00f4 vu\u00f4ng nh\u1ecf l\u00e0 18 \u00f4. Do \u0111\u00f3 khi chia t\u1ea5m b\u00eca th\u00e0nh 6 ph\u1ea7n gi\u1ed1ng h\u1ec7t nhau v\u1ec1 h\u00ecnh d\u1ea1ng th\u00ec m\u1ed7i ph\u1ea7n s\u1ebd c\u00f3 s\u1ed1 \u00f4 l\u00e0: 18 : 6 = 3 (\u00f4) v\u00e0 h\u00ecnh d\u1ea1ng m\u1ed7i ph\u1ea7n ph\u1ea3i c\u00f3 d\u1ea1ng h\u00ecnh ch\u1eef L.<\/p>\n

Ta c\u00f3 c\u00e1ch chia nh\u01b0 sau (c\u1eaft theo \u0111\u01b0\u1eddng k\u1ebb \u0111\u1eadm):<\/p>\n

\"90_2.jpg\"<\/p>\n

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

G\u1ee3i \u00fd:<\/p>\n

Bi\u1ec3u th\u1ecb s\u1ed1 ng\u01b0\u1eddi l\u00e0 1 \u0111o\u1ea1n th\u1eb3ng th\u00ec s\u1ed1 b\u00f4ng g\u1ed3m 5 \u0111o\u1ea1n th\u1eb3ng nh\u01b0 th\u1ebf v\u00e0 th\u00eam 5 n\u1eefa.<\/p>\n

N\u1ebfu th\u00eam 6 v\u00e0o s\u1ed1 b\u00f4ng n\u00f3i tr\u00ean th\u00ec \u0111\u1ee7 cho m\u1ed7i ng\u01b0\u1eddi 6 qu\u1ea3.<\/p>\n

Ta c\u00f3 s\u01a1 \u0111\u1ed3:<\/p>\n

S\u1ed1 ng\u01b0\u1eddi
\nS\u1ed1 b\u00f4ng
\nS\u1ed1 b\u00f4ng th\u00eam 6 qu\u1ea3<\/p>\n

\"91.jpg\"<\/p>\n

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

11 ng\u01b0\u1eddi
\n60 qu\u1ea3 b\u00f4ng.<\/p>\n

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

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

118 chia 3 = 39 d\u01b0 1<\/p>\n

118 chia 4 = 29 d\u01b0 2<\/p>\n

118 chia 5 = 23 d\u01b0 3<\/p>\n

= 118 b\u1eadc thang.<\/p>\n","protected":false},"excerpt":{"rendered":"

C\u00c2U 1: Cho d\u00e3y c\u00e1c s\u1ed1 ch\u1eb5n li\u00ean ti\u1ebfp: 2; 4; 6; 8; … ; 998; 1000. Sau khi \u0111i\u1ec1n th\u00eam c\u00e1c d\u1ea5u + ho\u1eb7c d\u1ea5u – v\u00e0o gi\u1eefa c\u00e1c s\u1ed1 theo \u00fd m\u00ecnh, b\u1ea1n B\u00ecnh th\u1ef1c hi\u1ec7n ph\u00e9p T\u00ednh \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0 2002; b\u1ea1n Minh th\u1ef1c hi\u1ec7n ph\u00e9p T\u00ednh \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0 […]<\/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-25429","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\/25429","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=25429"}],"version-history":[{"count":3,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25429\/revisions"}],"predecessor-version":[{"id":25575,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25429\/revisions\/25575"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=25429"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=25429"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=25429"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}