1001 toán tư duy lớp 2

["1001 B\u00c0I TO\u00c1N T\u01af DUY \u00e0 V\u00ed d\u1ee5 1: T\u00ecm x, bi\u1ebft x + 629 = 725 Gi\u1ea3i - Trong ph\u00e9p t\u00ednh tr\u00ean x \u0111\u00f3ng vai tr\u00f2 l\u00e0 s\u1ed1 h\u1ea1ng. Mu\u1ed1n t\u00ecm s\u1ed1 h\u1ea1ng ch\u01b0a bi\u1ebft, ta l\u1ea5y t\u1ed5ng tr\u1eeb \u0111i s\u1ed1 h\u1ea1ng kia. N\u00ean ta c\u00f3: x + 629 = 725 x = 725 - 629 x = 96\u2026........ \u00e0 V\u00ed d\u1ee5 2: T\u00ecm y, bi\u1ebft y - 643 = 261 Gi\u1ea3i - Trong ph\u00e9p t\u00ednh tr\u00ean y \u0111\u00f3ng vai tr\u00f2 l\u00e0 s\u1ed1 b\u1ecb tr\u1eeb. M\u00e0 mu\u1ed1n t\u00ecm s\u1ed1 b\u1ecb tr\u1eeb ta l\u1ea5y hi\u1ec7u c\u1ed9ng v\u1edbi s\u1ed1 tr\u1eeb. N\u00ean ta c\u00f3: y - 643 = 261 y = 261 + 643 y = 904.......... \u00e0 V\u00ed d\u1ee5 3: T\u00ecm x, bi\u1ebft 521 \u2013 x = 431 Gi\u1ea3i - Trong ph\u00e9p t\u00ednh tr\u00ean x \u0111\u00f3ng vai tr\u00f2 l\u00e0 s\u1ed1 tr\u1eeb. M\u00e0 mu\u1ed1n t\u00ecm s\u1ed1 tr\u1eeb ta l\u1ea5y s\u1ed1 b\u1ecb tr\u1eeb tr\u1eeb \u0111i hi\u1ec7u. N\u00ean ta c\u00f3: 521 \u2013 x = 431 x = 521 - 431 x = 90........... 51","B\u1ed9 c\u00e2u h\u1ecfi tr\u1eafc nghi\u1ec7m C\u00e2u 1: S\u1ed1 n\u00e0o trong c\u00e1c s\u1ed1 d\u01b0\u1edbi \u0111\u00e2y \u0111\u01b0\u1ee3c \u0111\u1ecdc l\u00e0: Hai tr\u0103m t\u00e1m m\u01b0\u01a1i C\u00e2u 2: S\u1ed1 d\u01b0\u1edbi \u0111\u00e2y \u0111\u01b0\u1ee3c \u0111\u1ecdc l\u00e0: C\u00e2u 3: Vi\u1ebft s\u1ed1, bi\u1ebft s\u1ed1 \u0111\u00f3 g\u1ed3m 6 ch\u1ee5c, 3 tr\u0103m v\u00e0 2 \u0111\u01a1n v\u1ecb C\u00e2u 4: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 c\u00f9ng k\u1ebft qu\u1ea3 v\u1edbi ph\u00e9p t\u00ednh sau: C\u00e2u 5: T\u00ednh t\u1ed5ng c\u1ee7a 112, 104 v\u00e0 161 App HOC247 Kids 52 kids.hoc247.vn","C\u00e2u 6: Vi\u1ebft th\u00eam 3 s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 ch\u1ea5m: C\u00e2u 7: T\u00ednh t\u1ed5ng c\u1ee7a s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 hai ch\u1eef s\u1ed1 v\u00e0 s\u1ed1 nh\u1ecf nh\u1ea5t c\u00f3 ba ch\u1eef s\u1ed1 kh\u00e1c nhau. C\u00e2u 8: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 k\u1ebft qu\u1ea3 l\u1edbn h\u01a1n k\u1ebft qu\u1ea3 c\u1ee7a ph\u00e9p t\u00ednh d\u01b0\u1edbi \u0111\u00e2y? C\u00e2u 9: T\u00ednh hi\u1ec7u c\u1ee7a 678, 89 v\u00e0 364 C\u00e2u 10: H\u00e3y ch\u1ecdn c\u00e2u tr\u1ea3 l\u1eddi \u0111\u00fang. App HOC247 Kids 53 kids.hoc247.vn","C\u00e2u 11: Tr\u00ean c\u00e1nh \u0111\u1ed3ng A thu ho\u1ea1ch \u0111\u01b0\u1ee3c 335kg t\u00e1o v\u00e0 nhi\u1ec1u h\u01a1n c\u00e1nh \u0111\u1ed3ng B 58kg t\u00e1o. H\u1ecfi c\u00e1nh \u0111\u1ed3ng B thu ho\u1ea1ch \u0111\u01b0\u1ee3c bao nhi\u00eau ki \u2013 l\u00f4 \u2013 gam t\u00e1o? C\u00e2u 12: T\u00ecm x, bi\u1ebft: C\u00e2u 13: T\u00ednh hi\u1ec7u c\u1ee7a s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 ba ch\u1eef s\u1ed1 kh\u00e1c nhau v\u00e0 s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 hai ch\u1eef s\u1ed1 kh\u00e1c nhau. C\u00e2u 14: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 k\u1ebft qu\u1ea3 l\u1edbn h\u01a1n k\u1ebft qu\u1ea3 c\u1ee7a ph\u00e9p t\u00ednh d\u01b0\u1edbi \u0111\u00e2y? C\u00e2u 15: T\u00ednh t\u1ed5ng c\u1ee7a s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 hai ch\u1eef s\u1ed1 v\u00e0 s\u1ed1 b\u00e9 nh\u1ea5t c\u00f3 hai ch\u1eef s\u1ed1 \u0111\u01b0\u1ee3c l\u1eadp t\u1eeb c\u00e1c s\u1ed1 6, 8 v\u00e0 9. App HOC247 Kids 54 kids.hoc247.vn","C\u00e2u 16: T\u00ednh: 451km + 89km = ? C\u00e2u 17: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 c\u00f9ng k\u1ebft qu\u1ea3 v\u1edbi ph\u00e9p t\u00ednh d\u01b0\u1edbi \u0111\u00e2y? C\u00e2u 18: \u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 ch\u1ea5m: 7m = . . .cm C\u00e2u 19: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 c\u00f9ng k\u1ebft qu\u1ea3 v\u1edbi ph\u00e9p t\u00ednh d\u01b0\u1edbi \u0111\u00e2y? C\u00e2u 20: M\u1ed9t qu\u1ea3 t\u1ea1 n\u1eb7ng 5kg v\u00e0 1 bao g\u1ea1o n\u1eb7ng 50kg c\u00f9ng b\u1ecf l\u00ean c\u00e1n c\u00e2n th\u0103ng b\u1eb1ng. H\u1ecfi c\u1ea7n c\u00f3 m\u1ea5y qu\u1ea3 t\u1ea1 \u0111\u1ec3 hai b\u00ean c\u00e2n b\u1eb1ng nhau? App HOC247 Kids 55 kids.hoc247.vn","C\u00e2u 21: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 k\u1ebft qu\u1ea3 l\u00e0: C\u00e2u 22: C\u00f3 m\u1ed9t can 5 l\u00edt v\u00e0 m\u1ed9t can 3 l\u00edt. H\u1ecfi l\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 \u0111ong \u0111\u01b0\u1ee3c 2 l\u00edt n\u01b0\u1edbc t\u1eeb hai can \u0111\u00f3 C\u00e2u 23: Trong h\u00ecnh \u1ea3nh n\u00e0o c\u00f3 \u00edt c\u00e2y th\u01b0\u1edbc nh\u1ea5t? C\u00e2u 24: Quan s\u00e1t h\u00ecnh \u1ea3nh v\u00e0 cho bi\u1ebft \u0111\u1ed3 v\u1eadt n\u00e0o c\u00f3 nhi\u1ec1u nh\u1ea5t? App HOC247 Kids 56 kids.hoc247.vn","C\u00e2u 25: C\u00f3 t\u1ea5t c\u1ea3 28 \u0111\u1ed3 v\u1eadt bao g\u1ed3m 4 lo\u1ea1i m\u00e0u: xanh, \u0111\u1ecf, t\u00edm, v\u00e0ng. Bi\u1ebft r\u1eb1ng m\u1ed7i lo\u1ea1i c\u00f3 \u00edt nh\u1ea5t 5 v\u1eadt, nhi\u1ec1u nh\u1ea5t 9 v\u1eadt v\u00e0 s\u1ed1 v\u1eadt c\u1ee7a m\u1ed7i lo\u1ea1i m\u00e0u l\u00e0 kh\u00e1c nhau. H\u1ecfi c\u00f3 bao nhi\u00eau v\u1eadt m\u00e0u \u0111\u1ecf, n\u1ebfu m\u00e0u \u0111\u1ecf c\u00f3 \u00edt v\u1eadt nh\u1ea5t. C\u00e2u 26: D\u1ef1a v\u00e0o s\u01a1 \u0111\u1ed3 tranh, c\u00f3 t\u1ea5t c\u1ea3 bao nhi\u00eau qu\u1ea3 c\u00e1c lo\u1ea1i? C\u00e2u 27: D\u1ef1a v\u00e0o bi\u1ec3u \u0111\u1ed3 tranh, cho bi\u1ebft lo\u1ea1i tr\u00e1i c\u00e2y n\u00e0o \u00edt nh\u1ea5t? C\u00e2u 28: Tr\u00ean b\u00e0n c\u00f3 c\u00e1c lo\u1ea1i tr\u00e1i c\u00e2y sau. B\u1ecbt m\u1eaft v\u00e0 ch\u1ecdn 2 qu\u1ea3. Ch\u1ecdn c\u00e2u sai trong c\u00e1c c\u00e2u d\u01b0\u1edbi \u0111\u00e2y. App HOC247 Kids 57 kids.hoc247.vn","\u0110\u00e1p \u00e1n ch\u1ee7 \u0111\u1ec1 4 C\u00e2u 1: S\u1ed1 n\u00e0o trong c\u00e1c s\u1ed1 d\u01b0\u1edbi \u0111\u00e2y \u0111\u01b0\u1ee3c \u0111\u1ecdc l\u00e0: Hai tr\u0103m t\u00e1m m\u01b0\u01a1i C\u00e2u 2: S\u1ed1 d\u01b0\u1edbi \u0111\u00e2y \u0111\u01b0\u1ee3c \u0111\u1ecdc l\u00e0: C\u00e2u 3: Vi\u1ebft s\u1ed1, bi\u1ebft s\u1ed1 \u0111\u00f3 g\u1ed3m 6 ch\u1ee5c, 3 tr\u0103m v\u00e0 2 \u0111\u01a1n v\u1ecb C\u00e2u 4: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 c\u00f9ng k\u1ebft qu\u1ea3 v\u1edbi ph\u00e9p t\u00ednh sau: C\u00e2u 5: T\u00ednh t\u1ed5ng c\u1ee7a 112, 104 v\u00e0 161 App HOC247 Kids 58 kids.hoc247.vn","C\u00e2u 6: Vi\u1ebft th\u00eam 3 s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 ch\u1ea5m: C\u00e2u 7: T\u00ednh t\u1ed5ng c\u1ee7a s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 hai ch\u1eef s\u1ed1 v\u00e0 s\u1ed1 nh\u1ecf nh\u1ea5t c\u00f3 ba ch\u1eef s\u1ed1 kh\u00e1c nhau. C\u00e2u 8: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 k\u1ebft qu\u1ea3 l\u1edbn h\u01a1n k\u1ebft qu\u1ea3 c\u1ee7a ph\u00e9p t\u00ednh d\u01b0\u1edbi \u0111\u00e2y? C\u00e2u 9: T\u00ednh hi\u1ec7u c\u1ee7a 678, 89 v\u00e0 364 59 C\u00e2u 10: H\u00e3y ch\u1ecdn c\u00e2u tr\u1ea3 l\u1eddi \u0111\u00fang. App HOC247 Kids kids.hoc247.vn","C\u00e2u 11: Tr\u00ean c\u00e1nh \u0111\u1ed3ng A thu ho\u1ea1ch \u0111\u01b0\u1ee3c 335kg t\u00e1o v\u00e0 nhi\u1ec1u h\u01a1n c\u00e1nh \u0111\u1ed3ng B 58kg t\u00e1o. H\u1ecfi c\u00e1nh \u0111\u1ed3ng B thu ho\u1ea1ch \u0111\u01b0\u1ee3c bao nhi\u00eau ki \u2013 l\u00f4 \u2013 gam t\u00e1o? C\u00e2u 12: T\u00ecm x, bi\u1ebft: C\u00e2u 13: T\u00ednh hi\u1ec7u c\u1ee7a s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 ba ch\u1eef s\u1ed1 kh\u00e1c nhau v\u00e0 s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 hai ch\u1eef s\u1ed1 kh\u00e1c nhau. C\u00e2u 14: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 k\u1ebft qu\u1ea3 l\u1edbn h\u01a1n k\u1ebft qu\u1ea3 c\u1ee7a ph\u00e9p t\u00ednh d\u01b0\u1edbi \u0111\u00e2y? C\u00e2u 15: T\u00ednh t\u1ed5ng c\u1ee7a s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 hai ch\u1eef s\u1ed1 v\u00e0 s\u1ed1 b\u00e9 nh\u1ea5t c\u00f3 hai ch\u1eef s\u1ed1 \u0111\u01b0\u1ee3c l\u1eadp t\u1eeb c\u00e1c s\u1ed1 6, 8 v\u00e0 9. App HOC247 Kids 60 kids.hoc247.vn","C\u00e2u 16: T\u00ednh: 451km + 89km = ? C\u00e2u 17: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 c\u00f9ng k\u1ebft qu\u1ea3 v\u1edbi ph\u00e9p t\u00ednh d\u01b0\u1edbi \u0111\u00e2y? C\u00e2u 18: \u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 ch\u1ea5m: 7m = . . .cm C\u00e2u 19: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 c\u00f9ng k\u1ebft qu\u1ea3 v\u1edbi ph\u00e9p t\u00ednh d\u01b0\u1edbi \u0111\u00e2y? C\u00e2u 20: M\u1ed9t qu\u1ea3 t\u1ea1 n\u1eb7ng 5kg v\u00e0 1 bao g\u1ea1o n\u1eb7ng 50kg c\u00f9ng b\u1ecf l\u00ean c\u00e1n c\u00e2n th\u0103ng b\u1eb1ng. H\u1ecfi c\u1ea7n c\u00f3 m\u1ea5y qu\u1ea3 t\u1ea1 \u0111\u1ec3 hai b\u00ean c\u00e2n b\u1eb1ng nhau? App HOC247 Kids 61 kids.hoc247.vn","C\u00e2u 21: Ph\u00e9p t\u00ednh n\u00e0o c\u00f3 k\u1ebft qu\u1ea3 l\u00e0: C\u00e2u 22: C\u00f3 m\u1ed9t can 5 l\u00edt v\u00e0 m\u1ed9t can 3 l\u00edt. H\u1ecfi l\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 \u0111ong \u0111\u01b0\u1ee3c 2 l\u00edt n\u01b0\u1edbc t\u1eeb hai can \u0111\u00f3 C\u00e2u 23: Trong h\u00ecnh \u1ea3nh n\u00e0o c\u00f3 \u00edt c\u00e2y th\u01b0\u1edbc nh\u1ea5t? C\u00e2u 24: Quan s\u00e1t h\u00ecnh \u1ea3nh v\u00e0 cho bi\u1ebft \u0111\u1ed3 v\u1eadt n\u00e0o c\u00f3 nhi\u1ec1u nh\u1ea5t? App HOC247 Kids 62 kids.hoc247.vn","C\u00e2u 25: C\u00f3 t\u1ea5t c\u1ea3 28 \u0111\u1ed3 v\u1eadt bao g\u1ed3m 4 lo\u1ea1i m\u00e0u: xanh, \u0111\u1ecf, t\u00edm, v\u00e0ng. Bi\u1ebft r\u1eb1ng m\u1ed7i lo\u1ea1i c\u00f3 \u00edt nh\u1ea5t 5 v\u1eadt, nhi\u1ec1u nh\u1ea5t 9 v\u1eadt v\u00e0 s\u1ed1 v\u1eadt c\u1ee7a m\u1ed7i lo\u1ea1i m\u00e0u l\u00e0 kh\u00e1c nhau. H\u1ecfi c\u00f3 bao nhi\u00eau v\u1eadt m\u00e0u \u0111\u1ecf, n\u1ebfu m\u00e0u \u0111\u1ecf c\u00f3 \u00edt v\u1eadt nh\u1ea5t. C\u00e2u 26: D\u1ef1a v\u00e0o s\u01a1 \u0111\u1ed3 tranh, c\u00f3 t\u1ea5t c\u1ea3 bao nhi\u00eau qu\u1ea3 c\u00e1c lo\u1ea1i? C\u00e2u 27: D\u1ef1a v\u00e0o bi\u1ec3u \u0111\u1ed3 tranh, cho bi\u1ebft lo\u1ea1i tr\u00e1i c\u00e2y n\u00e0o \u00edt nh\u1ea5t? C\u00e2u 28: Tr\u00ean b\u00e0n c\u00f3 c\u00e1c lo\u1ea1i tr\u00e1i c\u00e2y sau. B\u1ecbt m\u1eaft v\u00e0 ch\u1ecdn 2 qu\u1ea3. Ch\u1ecdn c\u00e2u sai trong c\u00e1c c\u00e2u d\u01b0\u1edbi \u0111\u00e2y. App HOC247 Kids 63 kids.hoc247.vn","1001 B\u00c0I TO\u00c1N T\u01af DUY Ch\u1ee7 \u0111\u1ec1 5: \u0110\u1ed3ng h\u1ed3. Tr\u1ed3ng c\u00e2y. Tu\u1ed5i I. Ki\u1ebfn th\u1ee9c tr\u1ecdng t\u00e2m 1. Th\u1eddi gian - Kho\u1ea3ng c\u00e1ch gi\u1eefa 2 s\u1ed1 li\u00ean ti\u1ebfp nhau tr\u00ean \u0111\u1ed3ng h\u1ed3 l\u00e0 5 ph\u00fat. N\u00ean \u0111\u1ec3 t\u00ednh nhanh s\u1ed1 ph\u00fat tr\u00ean \u0111\u1ed3ng h\u1ed3, ta l\u1ea5y: S\u1ed1 m\u00e0 kim ph\u00fat ch\u1ec9 v\u00e0o x 5 \u00e0 V\u00ed d\u1ee5: \u0110\u1ed3ng h\u1ed3 n\u00e0y c\u00f3 kim ng\u1eafn ch\u1ec9 v\u00e0o s\u1ed1 5 l\u00e0 5 gi\u1edd. Kim d\u00e0i ch\u1ec9 v\u00e0o s\u1ed1 6, v\u1eady s\u1ed1 ph\u00fat l\u00e0: 6 x 5 = 30 ph\u00fat V\u1eady \u0111\u1ed3ng h\u1ed3 \u0111ang ch\u1ec9 5 gi\u1edd 30 ph\u00fat - Khi kim ph\u00fat ch\u1ec9 v\u00e0o c\u00e1c s\u1ed1 l\u1edbn h\u01a1n 6 v\u00e0 nh\u1ecf h\u01a1n 12 th\u00ec \u0111\u1ed3ng h\u1ed3 \u0111\u00f3 c\u00f3 c\u00e1ch n\u00f3i gi\u1edd k\u00e9m. + \u0110\u1ec3 n\u00f3i gi\u1edd k\u00e9m ta d\u1ef1a v\u00e0o gi\u1edd c\u1ee7a \u0111\u1ed3ng h\u1ed3. N\u1ebfu hi\u1ec7n t\u1ea1i l\u00e0 6 gi\u1edd 40 ph\u00fat th\u00ec gi\u1edd k\u00e9m s\u1ebd l\u00e0 7 gi\u1edd k\u00e9m 20 ph\u00fat. V\u1eady \u0111\u1ec3 n\u00f3i gi\u1edd k\u00e9m ta th\u1ef1c hi\u1ec7n nh\u01b0 sau: (Gi\u1edd hi\u1ec7n t\u1ea1i + 1) gi\u1edd k\u00e9m (60 \u2013 s\u1ed1 ph\u00fat hi\u1ec7n t\u1ea1i) ph\u00fat \u00e0V\u00ed d\u1ee5: Gi\u1edd hi\u1ec7n t\u1ea1i l\u00e0 7 gi\u1edd 35 ph\u00fat. 7 : 35 V\u1eady ta c\u00f3 c\u00e1ch n\u00f3i gi\u1edd k\u00e9m l\u00e0: (7+ 1) gi\u1edd k\u00e9m (60 \u2013 35) ph\u00fat V\u1eady \u0111\u1ed3ng h\u1ed3 \u0111ang ch\u1ec9 8 gi\u1edd k\u00e9m 25 ph\u00fat 64","1001 B\u00c0I TO\u00c1N T\u01af DUY - \u0110\u1ec3 t\u00ednh gi\u1edd b\u1eaft \u0111\u1ea7u, gi\u1edd k\u1ebft th\u00fac v\u00e0 kho\u1ea3ng th\u1eddi gian ta s\u1eed d\u1ee5ng s\u01a1 \u0111\u1ed3 th\u1eddi gian. \u00e0 V\u00ed d\u1ee5: Hai chi\u1ebfc \u0111\u1ed3ng h\u1ed3 d\u01b0\u1edbi \u0111\u00e2y ch\u1ec9 th\u1eddi gian b\u1eaft \u0111\u1ea7u v\u00e0 th\u1eddi gian k\u1ebft th\u00fac b\u1eefa ti\u1ec7c sinh nh\u1eadt c\u1ee7a An. Cho bi\u1ebft b\u1eefa ti\u1ec7c \u0111\u00f3 k\u00e9o d\u00e0i bao l\u00e2u? Gi\u1ea3i T\u00ednh b\u1eefa ti\u1ec7c k\u00e9o d\u00e0i trong bao l\u00e2u ch\u00ednh l\u00e0 t\u00ednh kho\u1ea3ng th\u1eddi gian. V\u00e0 ta c\u00f3 th\u1eddi gian b\u1eaft \u0111\u1ea7u l\u00e0 2 gi\u1edd 30 ph\u00fat, th\u1eddi gian k\u1ebft th\u00fac l\u00e0 6 gi\u1edd 15 ph\u00fat. Ta c\u00f3 s\u01a1 \u0111\u1ed3 th\u1eddi gian nh\u01b0 sau V\u1eady bu\u1ed5i ti\u1ec7c k\u00e9o d\u00e0i trong 4 gi\u1edd 15 ph\u00fat. 2. B\u00e0i to\u00e1n tr\u1ed3ng c\u00e2y - T\u00ednh kho\u1ea3ng c\u00e1ch: + B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh s\u1ed1 kho\u1ea3ng c\u00e1ch gi\u1eefa c\u00e1c c\u00e2y v\u00e0 kho\u1ea3ng c\u00e1ch gi\u1eefa 2 c\u00e2y li\u1ec1n k\u1ec1 nhau. + B\u01b0\u1edbc 2: C\u00f3 bao nhi\u00eau kho\u1ea3ng c\u00e1ch th\u00ec c\u00f3 b\u1ea5y nhi\u00eau kho\u1ea3ng c\u00e1ch gi\u1eefa 2 c\u00e2y li\u1ec1n k\u1ec1 c\u1ed9ng l\u1ea1i v\u1edbi nhau. \u00e0 V\u00ed d\u1ee5: C\u00f3 3 c\u00e2y xanh, kho\u1ea3ng c\u00e1ch gi\u1eefa 2 c\u00e2y l\u00e0 2m. V\u1eady 2 c\u00e2y ngo\u00e0i c\u00f9ng c\u00e1ch nhau bao nhi\u00eau m\u00e9t? 65","1001 B\u00c0I TO\u00c1N T\u01af DUY Gi\u1ea3i S\u1ed1 kho\u1ea3ng c\u00e1ch c\u1ee7a hai c\u00e2y ngo\u00e0i c\u00f9ng l\u00e0 2 v\u00e0 kho\u1ea3ng c\u00e1ch gi\u1eefa 2 c\u00e2y li\u1ec1n k\u1ec1 l\u00e0 2m. V\u1eady ta c\u00f3 hai c\u00e2y ngo\u00e0i c\u00f9ng c\u00e1ch nhau s\u1ed1 m\u00e9t l\u00e0: 2 + 2 = 4 (m) \u0110\u00e1p s\u1ed1: 4m - T\u00ednh s\u1ed1 kho\u1ea3ng c\u00e1ch = S\u1ed1 c\u00e2y - 1 \u00e0V\u00ed d\u1ee5: V\u1edbi quy lu\u1eadt nh\u01b0 h\u00ecnh d\u01b0\u1edbi, c\u1ea7n bao nhi\u00eau gh\u1ebf gi\u1eefa 10 c\u00e2y xanh? Gi\u1ea3i Theo quy lu\u1eadt ta th\u1ea5y gi\u1eefa 2 c\u00e2y li\u00ean ti\u1ebfp c\u00f3 1 c\u00e1i gh\u1ebf. V\u1eady t\u00ednh s\u1ed1 c\u00e1i gh\u1ebf ch\u00ednh l\u00e0 t\u00ednh s\u1ed1 kho\u1ea3ng c\u00e1ch gi\u1eefa 10 c\u00e2y. C\u1ea7n s\u1ed1 s\u1ed1 gi\u1eefa 10 c\u00e2y xanh l\u00e0: 10 \u2013 1 = 9 (gh\u1ebf) \u0110\u00e1p s\u1ed1: 9 gh\u1ebf 3. B\u00e0i to\u00e1n v\u1ec1 tu\u1ed5i - T\u00ednh kho\u1ea3ng c\u00e1ch v\u1ec1 tu\u1ed5i c\u1ee7a 2 ng\u01b0\u1eddi = S\u1ed1 tu\u1ed5i l\u1edbn \u2013 S\u1ed1 tu\u1ed5i b\u00e9 L\u01b0u \u00fd: Kho\u1ea3ng c\u00e1ch v\u1ec1 tu\u1ed5i c\u1ee7a 2 ng\u01b0\u1eddi kh\u00f4ng thay \u0111\u1ed5i theo th\u1eddi gian \u00e0V\u00ed d\u1ee5 1: Candy 11 tu\u1ed5i, b\u1ed1 b\u1ea1n 36 tu\u1ed5i. H\u1ecfi sau 5 n\u0103m, b\u1ed1 h\u01a1n Candy bao nhi\u00eau tu\u1ed5i? Gi\u1ea3i 66","1001 B\u00c0I TO\u00c1N T\u01af DUY Hi\u1ec7n t\u1ea1i b\u1ed1 h\u01a1n con s\u1ed1 tu\u1ed5i l\u00e0: 36 \u2013 11 = 25 (tu\u1ed5i) Sau 5 n\u0103m n\u1eefa th\u00ec kho\u1ea3ng c\u00e1ch tu\u1ed5i gi\u1eefa b\u1ed1 vfa con kh\u00f4ng thay \u0111\u1ed5i v\u00e0 v\u1eabn l\u00e0 25 tu\u1ed5i. \u0110\u00e1p s\u1ed1: 25 tu\u1ed5i \u00e0 V\u00ed d\u1ee5 2: D\u00ec 31 tu\u1ed5i, m\u1eb9 35 tu\u1ed5i, Min 7 tu\u1ed5i. H\u1ecfi bao nhi\u00eau n\u0103m n\u1eefa th\u00ec t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a c\u1ea3 ba ng\u01b0\u1eddi l\u00e0 100? Gi\u1ea3i T\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a 3 ng\u01b0\u1eddi l\u00e0: 31 + 35 + 7 = 73 (tu\u1ed5i) S\u1ed1 tu\u1ed5i c\u1ea7n \u0111\u1ec3 t\u1ed5ng s\u1ed1 tu\u1ed5i l\u00e0 100 l\u00e0: 100 - 73 = 27 (tu\u1ed5i) S\u1ed1 n\u0103m c\u1ea7n t\u00ecm l\u00e0: 27 : 3 = 9 (n\u0103m) V\u1eady sau 9 n\u0103m n\u1eefa th\u00ec t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a 3 ng\u01b0\u1eddi l\u00e0 100. 67","B\u1ed9 c\u00e2u h\u1ecfi tr\u1eafc nghi\u1ec7m C\u00e2u 1: \u0110\u1ed3ng h\u1ed3 n\u00e0o ch\u1ec9 5 gi\u1edd k\u00e9m 10 ph\u00fat? C\u00e2u 2: H\u00e3y ch\u1ecdn th\u1eddi gian ch\u00ednh x\u00e1c c\u1ee7a chi\u1ebfc \u0111\u1ed3ng h\u1ed3 n\u00e0y? C\u00e2u 3: Chi\u1ebfc \u0111\u1ed3ng h\u1ed3 d\u01b0\u1edbi \u0111\u00e2y l\u00e0 h\u00ecnh \u1ea3nh ph\u1ea3n chi\u1ebfu qua g\u01b0\u01a1ng. H\u00e3y ch\u1ecdn th\u1eddi gian ch\u00ednh x\u00e1c c\u1ee7a chi\u1ebfc \u0111\u1ed3ng h\u1ed3 n\u00e0y? App HOC247 Kids 68 kids.hoc247.vn","C\u00e2u 4: C\u1ee9 5 ph\u00fat c\u00f3 m\u1ed9t chuy\u1ebfn t\u00e0u \u0111i\u1ec7n ng\u1ea7m t\u1edbi ga. H\u1ecfi trong 30 ph\u00fat s\u1ebd c\u00f3 bao nhi\u00eau chuy\u1ebfn t\u00e0u \u0111i\u1ec7n ng\u1ea7m t\u1edbi ga? C\u00e2u 5: T\u1eeb 5 gi\u1edd 30 ph\u00fat th\u00ec c\u1ee9 10 ph\u00fat s\u1ebd c\u00f3 m\u1ed9t chuy\u1ebfn xe kh\u00e1ch r\u1eddi b\u1ebfn. H\u1ecfi t\u1eeb 5 gi\u1edd 30 ph\u00fat \u0111\u1ebfn 6 gi\u1edd 30 ph\u00fat th\u00ec t\u1ed5ng c\u1ed9ng bao nhi\u00eau chuy\u1ebfn xe r\u1eddi b\u1ebfn? C\u00e2u 6: L\u1edbp b\u1ea1n Linh t\u1ed5 ch\u1ee9c \u0111i tham quan c\u00f4ng vi\u00ean, c\u00e1c b\u1ea1n h\u1ecdc sinh xu\u1ea5t ph\u00e1t t\u1eeb tr\u01b0\u1eddng l\u00fac m\u1ea5y gi\u1edd bi\u1ebft c\u00e1c b\u1ea1n \u0111\u1ebfn c\u00f4ng vi\u00ean l\u00fac 8 gi\u1edd 00 v\u00e0 th\u1eddi gian di chuy\u1ec3n h\u1ebft 30 ph\u00fat? C\u00e2u 7: Kim gi\u1edd v\u00e0 kim ph\u00fat \u1edf \u0111\u1ed3ng h\u1ed3 k\u1ebf ti\u1ebfp \u1edf v\u1ecb tr\u00ed bao nhi\u00eau gi\u1edd? App HOC247 Kids 69 kids.hoc247.vn","C\u00e2u 8: C\u00f3 bao nhi\u00eau kho\u1ea3ng c\u00e1ch gi\u1eefa c\u00e1c vi\u00ean k\u1eb9o sau: C\u00e2u 9: C\u1ee9 2 c\u00e2y xanh th\u00ec c\u00e1ch nhau 3 m\u00e9t, N\u1ebfu tr\u1ed3ng 1 d\u00e3y 5 c\u00e2y xanh c\u00e1ch \u0111\u1ec1u nhau. Kho\u1ea3ng c\u00e1ch c\u1ee7a c\u00e2y th\u1ee9 nh\u1ea5t \u0111\u1ebfn c\u00e2y th\u1ee9 5 l\u00e0 bao nhi\u00eau m\u00e9t? C\u00e2u 10: M\u1ed9t to\u00e0 nh\u00e0 c\u00f3 4 t\u1ea7ng t\u00ednh c\u1ea3 t\u1ea7ng tr\u1ec7t. M\u1ed7i t\u1ea7ng cao 4m, ri\u00eang m\u00e1i nh\u00e0 cao 2m. H\u1ecfi to\u00e0 nh\u00e0 \u0111\u00f3 cao bao nhi\u00eau? C\u00e2u 11: An mu\u1ed1n leo l\u00ean nh\u00e0 \u1edf t\u1ea7ng 4 kh\u00f4ng t\u00ednh t\u1ea7ng tr\u1ec7t ph\u1ea3i \u0111i l\u00ean 36 b\u1eadc thang. M\u1ed7i b\u1eadc thang c\u1ee7a t\u1eebng l\u1ea7u \u0111\u1ec1u b\u1eb1ng nhau. H\u1ecfi s\u1ed1 b\u1eadc thang c\u1ee7a m\u1ed7i t\u1ea7ng? App HOC247 Kids 70 kids.hoc247.vn","C\u00e2u 12: M\u1ed9t b\u1ebfn xe c\u1ee9 5 ph\u00fat th\u00ec c\u00f3 m\u1ed9t chuy\u1ebfn xe xu\u1ea5t b\u1ebfn. H\u1ecfi trong 30 ph\u00fat th\u00ec c\u00f3 bao nhi\u00eau xe xu\u1ea5t b\u1ebfn? C\u00e2u 13: T\u1eeb h\u00ecnh \u1ea3nh, em h\u00e3y cho bi\u1ebft th\u1eddi gian B\u00ecnh ch\u1ea1y t\u1eeb nh\u00e0 \u0111\u1ebfn c\u00f4ng vi\u00ean: C\u00e2u 14: MiMi x\u1ebfp m\u1ed9t s\u1ed1 \u0111\u1ed3ng xu th\u00e0nh h\u00ecnh ch\u1eef nh\u1eadt. M\u1ed7i g\u00f3c c\u1ee7a h\u00ecnh ch\u1eef nh\u1eadt l\u00e0 m\u1ed9t \u0111\u1ed3ng xu. V\u00e0 tr\u00ean c\u1ea1nh chi\u1ec1u d\u00e0i c\u1ee7a h\u00ecnh ch\u1eef nh\u1eadt c\u00f3 5 \u0111\u1ed3ng xu, c\u1ea1nh chi\u1ec1u r\u1ed9ng c\u00f3 3 \u0111\u1ed3ng xu. H\u1ecfi MiMi d\u00f9ng bao nhi\u00eau \u0111\u1ed3ng xu \u0111\u1ec3 x\u1ebfp th\u00e0nh h\u00ecnh ch\u1eef nh\u1eadt? App HOC247 Kids 71 kids.hoc247.vn","C\u00e2u 15: Ch\u1ecdn c\u00e1c s\u1ed1 sau v\u00e0o v\u1ecb tr\u00ed theo th\u1ee9 t\u1ef1 ph\u00f9 h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 t\u1ea1o th\u00e0nh ph\u00e9p t\u00ednh c\u1ed9ng: C\u00e2u 16: Thay s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ph\u00e9p t\u00ednh sau: C\u00e2u 17: T\u00ednh nhanh: 72 App HOC247 Kids kids.hoc247.vn","C\u00e2u 18: Ch\u1ecdn c\u00e1c s\u1ed1 th\u00edch h\u1ee3p theo th\u1ee9 t\u1ef1 ph\u00f9 h\u1ee3p. Bi\u1ec3u di\u1ec5n s\u1ed1 d\u01b0\u1edbi d\u1ea1ng t\u1ed5ng c\u1ee7a 2 s\u1ed1: 47 = ___+ 17 = 27 +___ C\u00e2u 19: Ch\u1ecdn s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 t\u1ea1o th\u00e0nh ph\u00e9p t\u00ednh c\u1ed9ng: 2__+ __5 = 39 C\u00e2u 20: K\u1ebft qu\u1ea3 c\u1ee7a ph\u00e9p t\u00ednh sau l\u00e0? C\u00e2u 21: Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang. Cho ph\u00e9p t\u00ednh bi\u1ec3u di\u1ec5n s\u1ed1 d\u01b0\u1edbi d\u1ea1ng t\u1ed5ng c\u1ee7a 3 s\u1ed1: App HOC247 Kids 73 kids.hoc247.vn","C\u00e2u 22: T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a c\u00e2y kem? C\u00e2u 23: Em h\u00e3y t\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u00e1m m\u00e2y? C\u00e2u 24: T\u00ecm b\u00f4ng hoa? C\u00e2u 25: B\u00e9 h\u00e3y t\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a ng\u00f4i sao? App HOC247 Kids 74 kids.hoc247.vn","C\u00e2u 26: \u0110i\u1ec1n v\u00e0o d\u1ea5u ? C\u00e2u 27: T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a c\u00e2y k\u1eb9o m\u00fat? C\u00e2u 28: T\u00ecm gi\u00e1 tr\u1ecb qu\u1ea3 d\u00e2u t\u00e2y d\u01b0\u1edbi \u0111\u00e2y? App HOC247 Kids 75 kids.hoc247.vn","C\u00e2u 29: Joe 6 tu\u1ed5i. S\u1ed1 tu\u1ed5i c\u1ee7a Jack g\u1ea5p 3 l\u1ea7n s\u1ed1 tu\u1ed5i c\u1ee7a Joe. H\u1ecfi Jack bao nhi\u00eau tu\u1ed5i? C\u00e2u 30: Con 1 tu\u1ed5i, m\u1eb9 21 tu\u1ed5i. H\u1ecfi sau bao nhi\u00eau n\u0103m tu\u1ed5i m\u1eb9 g\u1ea5p 6 l\u1ea7n tu\u1ed5i con? C\u00e2u 31: B\u00e0 65 tu\u1ed5i, Rose 12 tu\u1ed5i, Andy 3 tu\u1ed5i. H\u1ecfi 5 n\u0103m n\u1eefa, t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a b\u00e0, Rose v\u00e0 Andy l\u00e0 bao nhi\u00eau? App HOC247 Kids 76 kids.hoc247.vn","C\u00e2u 32: Ch\u00fa Minh nhi\u1ec1u h\u01a1n c\u00f4 Thy 2 tu\u1ed5i. 4 n\u0103m n\u1eefa, t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a c\u00f4 ch\u00fa \u1ea5y s\u1ebd l\u00e0 86. H\u1ecfi n\u0103m nay m\u1ed7i ng\u01b0\u1eddi bao nhi\u00eau tu\u1ed5i? C\u00e2u 33: Gia \u0111\u00ecnh ch\u00fa D\u0169ng v\u00e0 c\u00f4 Hi\u1ec1n c\u00f3 m\u1ed9t ng\u01b0\u1eddi con l\u00e0 Minh. Minh 11 tu\u1ed5i, c\u00f4 Hi\u1ec1n 31 tu\u1ed5i. Ch\u00fa D\u0169ng l\u1edbn h\u01a1n c\u00f4 6 tu\u1ed5i. H\u1ecfi sau bao nhi\u00eau n\u0103m n\u1eefa th\u00ec t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a c\u1ea3 3 ng\u01b0\u1eddi s\u1ebd l\u00e0 100? C\u00e2u 34: Ba 36 tu\u1ed5i, m\u1eb9 29 tu\u1ed5i, Linh 8 tu\u1ed5i, Bin 3 tu\u1ed5i. H\u1ecfi bao nhi\u00eau n\u0103m n\u1eefa th\u00ec t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a c\u1ea3 gia \u0111\u00ecnh l\u00e0 100? App HOC247 Kids 77 kids.hoc247.vn","C\u00e2u 35: N\u0103m nay, Tr\u00e0 12 tu\u1ed5i. T\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a Tr\u00e0 v\u00e0 anh trai sau 10 n\u0103m n\u1eefa l\u00e0 55 tu\u1ed5i. H\u1ecfi n\u0103m nay anh Tr\u00e0 bao nhi\u00eau tu\u1ed5i? App HOC247 Kids 78 kids.hoc247.vn","\u0110\u00e1p \u00e1n ch\u1ee7 \u0111\u1ec1 5 C\u00e2u 1: \u0110\u1ed3ng h\u1ed3 n\u00e0o ch\u1ec9 5 gi\u1edd k\u00e9m 10 ph\u00fat? C\u00e2u 2: H\u00e3y ch\u1ecdn th\u1eddi gian ch\u00ednh x\u00e1c c\u1ee7a chi\u1ebfc \u0111\u1ed3ng h\u1ed3 n\u00e0y? C\u00e2u 3: Chi\u1ebfc \u0111\u1ed3ng h\u1ed3 d\u01b0\u1edbi \u0111\u00e2y l\u00e0 h\u00ecnh \u1ea3nh ph\u1ea3n chi\u1ebfu qua g\u01b0\u01a1ng. H\u00e3y ch\u1ecdn th\u1eddi gian ch\u00ednh x\u00e1c c\u1ee7a chi\u1ebfc \u0111\u1ed3ng h\u1ed3 n\u00e0y? App HOC247 Kids 79 kids.hoc247.vn","C\u00e2u 4: C\u1ee9 5 ph\u00fat c\u00f3 m\u1ed9t chuy\u1ebfn t\u00e0u \u0111i\u1ec7n ng\u1ea7m t\u1edbi ga. H\u1ecfi trong 30 ph\u00fat s\u1ebd c\u00f3 bao nhi\u00eau chuy\u1ebfn t\u00e0u \u0111i\u1ec7n ng\u1ea7m t\u1edbi ga? C\u00e2u 5: T\u1eeb 5 gi\u1edd 30 ph\u00fat th\u00ec c\u1ee9 10 ph\u00fat s\u1ebd c\u00f3 m\u1ed9t chuy\u1ebfn xe kh\u00e1ch r\u1eddi b\u1ebfn. H\u1ecfi t\u1eeb 5 gi\u1edd 30 ph\u00fat \u0111\u1ebfn 6 gi\u1edd 30 ph\u00fat th\u00ec t\u1ed5ng c\u1ed9ng bao nhi\u00eau chuy\u1ebfn xe r\u1eddi b\u1ebfn? C\u00e2u 6: L\u1edbp b\u1ea1n Linh t\u1ed5 ch\u1ee9c \u0111i tham quan c\u00f4ng vi\u00ean, c\u00e1c b\u1ea1n h\u1ecdc sinh xu\u1ea5t ph\u00e1t t\u1eeb tr\u01b0\u1eddng l\u00fac m\u1ea5y gi\u1edd bi\u1ebft c\u00e1c b\u1ea1n \u0111\u1ebfn c\u00f4ng vi\u00ean l\u00fac 8 gi\u1edd 00 v\u00e0 th\u1eddi gian di chuy\u1ec3n h\u1ebft 30 ph\u00fat? C\u00e2u 7: Kim gi\u1edd v\u00e0 kim ph\u00fat \u1edf \u0111\u1ed3ng h\u1ed3 k\u1ebf ti\u1ebfp \u1edf v\u1ecb tr\u00ed bao nhi\u00eau gi\u1edd? App HOC247 Kids 80 kids.hoc247.vn","C\u00e2u 8: C\u00f3 bao nhi\u00eau kho\u1ea3ng c\u00e1ch gi\u1eefa c\u00e1c vi\u00ean k\u1eb9o sau: C\u00e2u 9: C\u1ee9 2 c\u00e2y xanh th\u00ec c\u00e1ch nhau 3 m\u00e9t, N\u1ebfu tr\u1ed3ng 1 d\u00e3y 5 c\u00e2y xanh c\u00e1ch \u0111\u1ec1u nhau. Kho\u1ea3ng c\u00e1ch c\u1ee7a c\u00e2y th\u1ee9 nh\u1ea5t \u0111\u1ebfn c\u00e2y th\u1ee9 5 l\u00e0 bao nhi\u00eau m\u00e9t? C\u00e2u 10: M\u1ed9t to\u00e0 nh\u00e0 c\u00f3 4 t\u1ea7ng t\u00ednh c\u1ea3 t\u1ea7ng tr\u1ec7t. M\u1ed7i t\u1ea7ng cao 4m, ri\u00eang m\u00e1i nh\u00e0 cao 2m. H\u1ecfi to\u00e0 nh\u00e0 \u0111\u00f3 cao bao nhi\u00eau? C\u00e2u 11: An mu\u1ed1n leo l\u00ean nh\u00e0 \u1edf t\u1ea7ng 4 kh\u00f4ng t\u00ednh t\u1ea7ng tr\u1ec7t ph\u1ea3i \u0111i l\u00ean 36 b\u1eadc thang. M\u1ed7i b\u1eadc thang c\u1ee7a t\u1eebng l\u1ea7u \u0111\u1ec1u b\u1eb1ng nhau. H\u1ecfi s\u1ed1 b\u1eadc thang c\u1ee7a m\u1ed7i t\u1ea7ng? App HOC247 Kids 81 kids.hoc247.vn","C\u00e2u 12: M\u1ed9t b\u1ebfn xe c\u1ee9 5 ph\u00fat th\u00ec c\u00f3 m\u1ed9t chuy\u1ebfn xe xu\u1ea5t b\u1ebfn. H\u1ecfi trong 30 ph\u00fat th\u00ec c\u00f3 bao nhi\u00eau xe xu\u1ea5t b\u1ebfn? C\u00e2u 13: T\u1eeb h\u00ecnh \u1ea3nh, em h\u00e3y cho bi\u1ebft th\u1eddi gian B\u00ecnh ch\u1ea1y t\u1eeb nh\u00e0 \u0111\u1ebfn c\u00f4ng vi\u00ean: C\u00e2u 14: MiMi x\u1ebfp m\u1ed9t s\u1ed1 \u0111\u1ed3ng xu th\u00e0nh h\u00ecnh ch\u1eef nh\u1eadt. M\u1ed7i g\u00f3c c\u1ee7a h\u00ecnh ch\u1eef nh\u1eadt l\u00e0 m\u1ed9t \u0111\u1ed3ng xu. V\u00e0 tr\u00ean c\u1ea1nh chi\u1ec1u d\u00e0i c\u1ee7a h\u00ecnh ch\u1eef nh\u1eadt c\u00f3 5 \u0111\u1ed3ng xu, c\u1ea1nh chi\u1ec1u r\u1ed9ng c\u00f3 3 \u0111\u1ed3ng xu. H\u1ecfi MiMi d\u00f9ng bao nhi\u00eau \u0111\u1ed3ng xu \u0111\u1ec3 x\u1ebfp th\u00e0nh h\u00ecnh ch\u1eef nh\u1eadt? App HOC247 Kids 82 kids.hoc247.vn","C\u00e2u 15: Ch\u1ecdn c\u00e1c s\u1ed1 sau v\u00e0o v\u1ecb tr\u00ed theo th\u1ee9 t\u1ef1 ph\u00f9 h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 t\u1ea1o th\u00e0nh ph\u00e9p t\u00ednh c\u1ed9ng: C\u00e2u 16: Thay s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ph\u00e9p t\u00ednh sau: C\u00e2u 17: T\u00ednh nhanh: App HOC247 Kids 83 kids.hoc247.vn","C\u00e2u 18: Ch\u1ecdn c\u00e1c s\u1ed1 th\u00edch h\u1ee3p theo th\u1ee9 t\u1ef1 ph\u00f9 h\u1ee3p. Bi\u1ec3u di\u1ec5n s\u1ed1 d\u01b0\u1edbi d\u1ea1ng t\u1ed5ng c\u1ee7a 2 s\u1ed1: 47 = ___+ 17 = 27 +___ C\u00e2u 19: Ch\u1ecdn s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 t\u1ea1o th\u00e0nh ph\u00e9p t\u00ednh c\u1ed9ng: 2__+ __5 = 39 C\u00e2u 20: K\u1ebft qu\u1ea3 c\u1ee7a ph\u00e9p t\u00ednh sau l\u00e0? C\u00e2u 21: Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang. Cho ph\u00e9p t\u00ednh bi\u1ec3u di\u1ec5n s\u1ed1 d\u01b0\u1edbi d\u1ea1ng t\u1ed5ng c\u1ee7a 3 s\u1ed1: App HOC247 Kids 84 kids.hoc247.vn","C\u00e2u 22: T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a c\u00e2y kem? C\u00e2u 23: Em h\u00e3y t\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u00e1m m\u00e2y? C\u00e2u 24: T\u00ecm b\u00f4ng hoa? C\u00e2u 25: B\u00e9 h\u00e3y t\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a ng\u00f4i sao? App HOC247 Kids 85 kids.hoc247.vn","C\u00e2u 26: \u0110i\u1ec1n v\u00e0o d\u1ea5u ? C\u00e2u 27: T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a c\u00e2y k\u1eb9o m\u00fat? C\u00e2u 28: T\u00ecm gi\u00e1 tr\u1ecb qu\u1ea3 d\u00e2u t\u00e2y d\u01b0\u1edbi \u0111\u00e2y? App HOC247 Kids 86 kids.hoc247.vn","C\u00e2u 29: Joe 6 tu\u1ed5i. S\u1ed1 tu\u1ed5i c\u1ee7a Jack g\u1ea5p 3 l\u1ea7n s\u1ed1 tu\u1ed5i c\u1ee7a Joe. H\u1ecfi Jack bao nhi\u00eau tu\u1ed5i? C\u00e2u 30: Con 1 tu\u1ed5i, m\u1eb9 21 tu\u1ed5i. H\u1ecfi sau bao nhi\u00eau n\u0103m tu\u1ed5i m\u1eb9 g\u1ea5p 6 l\u1ea7n tu\u1ed5i con? C\u00e2u 31: B\u00e0 65 tu\u1ed5i, Rose 12 tu\u1ed5i, Andy 3 tu\u1ed5i. H\u1ecfi 5 n\u0103m n\u1eefa, t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a b\u00e0, Rose v\u00e0 Andy l\u00e0 bao nhi\u00eau? App HOC247 Kids 87 kids.hoc247.vn","C\u00e2u 32: Ch\u00fa Minh nhi\u1ec1u h\u01a1n c\u00f4 Thy 2 tu\u1ed5i. 4 n\u0103m n\u1eefa, t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a c\u00f4 ch\u00fa \u1ea5y s\u1ebd l\u00e0 86. H\u1ecfi n\u0103m nay m\u1ed7i ng\u01b0\u1eddi bao nhi\u00eau tu\u1ed5i? C\u00e2u 33:Gia \u0111\u00ecnh ch\u00fa D\u0169ng v\u00e0 c\u00f4 Hi\u1ec1n c\u00f3 m\u1ed9t ng\u01b0\u1eddi con l\u00e0 Minh. Minh 11 tu\u1ed5i, c\u00f4 Hi\u1ec1n 31 tu\u1ed5i. Ch\u00fa D\u0169ng l\u1edbn h\u01a1n c\u00f4 6 tu\u1ed5i. H\u1ecfi sau bao nhi\u00eau n\u0103m n\u1eefa th\u00ec t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a c\u1ea3 3 ng\u01b0\u1eddi s\u1ebd l\u00e0 100? C\u00e2u 34: Ba 36 tu\u1ed5i, m\u1eb9 29 tu\u1ed5i, Linh 8 tu\u1ed5i, Bin 3 tu\u1ed5i. H\u1ecfi bao nhi\u00eau n\u0103m n\u1eefa th\u00ec t\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a c\u1ea3 gia \u0111\u00ecnh l\u00e0 100? App HOC247 Kids 88 kids.hoc247.vn","C\u00e2u 35: N\u0103m nay, Tr\u00e0 12 tu\u1ed5i. T\u1ed5ng s\u1ed1 tu\u1ed5i c\u1ee7a Tr\u00e0 v\u00e0 anh trai sau 10 n\u0103m n\u1eefa l\u00e0 55 tu\u1ed5i. H\u1ecfi n\u0103m nay anh Tr\u00e0 bao nhi\u00eau tu\u1ed5i? App HOC247 Kids 89 kids.hoc247.vn","1001 B\u00c0I TO\u00c1N T\u01af DUY Ch\u1ee7 \u0111\u1ec1 6: \u0110\u1ebfm. Quy t\u1eafc chung. Logic I. Ki\u1ebfn th\u1ee9c tr\u1ecdng t\u00e2m 1. Ph\u00e9p chia v\u00e0 quy lu\u1eadt - \u0110\u1ec3 bi\u1ebft t\u1ea1i th\u1ee9 t\u1ef1 s\u1ed1 a l\u00e0 s\u1ef1 v\u1eadt g\u00ec ta c\u1ea7n ph\u1ea3i: + B\u01b0\u1edbc 1: X\u00e9t quy lu\u1eadt s\u1eafp x\u1ebfp c\u1ee7a c\u00e1c s\u1ef1 v\u1eadt (sau m\u1ea5y s\u1ef1 v\u1eadt th\u00ec l\u1eb7p l\u1ea1i quy lu\u1eadt) + B\u01b0\u1edbc 2: L\u1ea5y s\u1ed1 th\u1ee9 t\u1ef1 c\u1ea7n t\u00ecm chia cho s\u1ed1 s\u1ef1 v\u1eadt trong m\u1ed9t v\u00f2ng l\u1eb7p \u0111\u1ec3 xem \u0111\u00f3 l\u00e0 ph\u00e9p chia c\u00f3 s\u1ed1 d\u01b0 l\u00e0 bao nhi\u00eau. + B\u01b0\u1edbc 3: \u0110\u00e1nh s\u1ed1 th\u1ee9 t\u1ef1 cho l\u1ea7n l\u01b0\u1ee3t c\u00e1c s\u1ef1 v\u1eadt trong m\u1ed9t v\u00f2ng l\u1eb7p t\u1eeb tr\u00e1i qua ph\u1ea3i, b\u1eaft \u0111\u1ea7u t\u1eeb 1. + B\u01b0\u1edbc 4: L\u1ea5y s\u1ed1 th\u1ee9 t\u1ef1 c\u00e1c s\u1ef1 v\u1eadt chia cho s\u1ed1 s\u1ef1 v\u1eadt trong m\u1ed9t v\u00f2ng l\u1eb7p. Ph\u00e9p chia n\u00e0o c\u00f3 s\u1ed1 d\u01b0 b\u1eb1ng ph\u00e9p chia \u1edf b\u01b0\u1edbc 2, th\u00ec s\u1ef1 v\u1eadt \u0111\u00f3 l\u00e0 s\u1ef1 v\u1eadt c\u1ea7n t\u00ecm. \u00e0 V\u00ed d\u1ee5: H\u00ecnh \u0111\u1ea7u ti\u00ean l\u00e0 ng\u00f4i sao v\u00e0 k\u1ebf ti\u1ebfp l\u00e0 m\u1eb7t tr\u0103ng. Ng\u00f4i sao v\u00e0 m\u1eb7t tr\u0103ng x\u1ebfp xen k\u1ebd nhau. H\u1ecfi h\u00ecnh th\u1ee9 10 l\u00e0 h\u00ecnh g\u00ec? Gi\u1ea3i 90","1001 B\u00c0I TO\u00c1N T\u01af DUY - Chia t\u00ednh ng\u00e0y: \u2022 C\u00e1ch 1: + B\u01b0\u1edbc 1: Vi\u1ebft l\u1ecbch b\u1eaft \u0111\u1ea7u t\u1eeb ng\u00e0y cho bi\u1ebft \u0111\u1ebfn ng\u00e0y c\u1ea7n t\u00ecm v\u00e0o b\u1ea3ng theo th\u1ee9 t\u1ef1 t\u1eeb tr\u00e1i qua ph\u1ea3i r\u1ed3i t\u1eeb tr\u00ean xu\u1ed1ng d\u01b0\u1edbi. + B\u01b0\u1edbc 2: D\u1ef1a v\u00e0o l\u1ecbch \u0111\u1ec3 t\u00ecm ra ng\u00e0y c\u1ea7n t\u00ecm. \u2022 C\u00e1ch 2: + B\u01b0\u1edbc 1: L\u1ea5y ng\u00e0y c\u1ea7n t\u00ecm chia cho 7 v\u00e0 x\u00e1c \u0111\u1ecbnh s\u1ed1 d\u01b0 c\u1ee7a ph\u00e9p chia. + B\u01b0\u1edbc 2: Th\u1ee9 c\u1ee7a ng\u00e0y \u0111\u00e3 cho ch\u00ednh l\u00e0 th\u1ee9 c\u00f3 s\u1ed1 d\u01b0 b\u1eb1ng 1. C\u1ee9 nh\u01b0 v\u1eady vi\u1ebft t\u1eeb 1 \u0111\u1ebfn 6 r\u1ed3i quay l\u1ea1i 0 cho c\u00e1c th\u1ee9 trong tu\u1ea7n. + B\u01b0\u1edbc 3: Th\u1ee9 n\u00e0o c\u00f3 s\u1ed1 d\u01b0 b\u1eb1ng v\u1edbi s\u1ed1 d\u01b0 c\u1ee7a ph\u00e9p chia \u1edf b\u01b0\u1edbc 1 th\u00ec \u0111\u00f3 ch\u00ednh l\u00e0 th\u1ee9 c\u1ea7n t\u00ecm. \u00e0 V\u00ed d\u1ee5: V\u00e0o m\u1ed9t n\u0103m n\u00e0o \u0111\u00f3, ng\u00e0y 1 th\u00e1ng Ba l\u00e0 ng\u00e0y Ch\u1ee7 nh\u1eadt. H\u1ecfi ng\u00e0y 25 th\u00e1ng Ba c\u00f9ng n\u0103m \u0111\u00f3 l\u00e0 th\u1ee9 m\u1ea5y trong tu\u1ea7n? 91","1001 B\u00c0I TO\u00c1N T\u01af DUY Theo \u0111\u1ec1 b\u00e0i ta c\u00f3 ng\u00e0y 1 th\u00e1ng T\u01b0 l\u00e0 Ch\u1ee7 nh\u1eadt, v\u1eady Ch\u1ee7 nh\u1eadt c\u00f3 s\u1ed1 d\u01b0 l\u00e0 1. 2. B\u00e0i to\u00e1n t\u00ecm s\u1ed1 s\u1ef1 v\u1eadt. - Khi b\u00e0i to\u00e1n cho bi\u1ebft t\u1ed5ng s\u1ed1 s\u1ef1 v\u1eadt v\u00e0 t\u1ed5ng gi\u00e1 tr\u1ecb c\u1ee7a s\u1ef1 v\u1eadt. + B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh gi\u00e1 tr\u1ecb m\u1ed7i s\u1ef1 v\u1eadt \u0111\u00f3. + B\u01b0\u1edbc 2: D\u1ef1a v\u00e0o d\u1eef ki\u1ebfn \u0111\u1ec1 b\u00e0i \u0111\u1ec3 l\u1eadp b\u1ea3ng gi\u00e1 tr\u1ecb \u0111\u1ec3 t\u00ecm \u0111\u01b0\u1ee3c s\u1ed1 s\u1ef1 v\u1eadt m\u1ed7i lo\u1ea1i. \u00e0 V\u00ed d\u1ee5: C\u00f3 6 con g\u00e0 v\u00e0 th\u1ecf, c\u00f3 t\u1ea5t c\u1ea3 c\u00f3 16 c\u00e1i ch\u00e2n. H\u1ecfi c\u00f3 bao nhi\u00eau con g\u00e0 v\u00e0 bao nhi\u00eau con th\u1ecf? Gi\u1ea3i - Ta x\u00e1c \u0111\u1ecbnh m\u1ed7i con g\u00e0 c\u00f3 2 ch\u00e2n v\u00e0 m\u1ed7i con th\u1ecf c\u00f3 4 ch\u00e2n. - V\u00ec t\u1ed5ng s\u1ed1 con v\u1eadt l\u00e0 6 n\u00ean ta s\u1ebd c\u00f3 c\u00e1c tr\u01b0\u1eddng h\u1ee3p sau: 3 + 3 = 6 v\u00e0 4 + 2 = 6 - T\u1ed5ng s\u1ed1 ch\u00e2n l\u00e0 16. V\u1eady ta s\u1ebd c\u00f3 b\u1ea3ng sau. 92","1001 B\u00c0I TO\u00c1N T\u01af DUY 3. Quy t\u1eafc d\u00e3y s\u1ed1 - D\u1ef1a v\u00e0o c\u00e1c s\u1ed1 \u0111\u1ec1 b\u00e0i \u0111\u00e3 cho t\u00ecm ra quy lu\u1eadt c\u1ee7a d\u00e3y s\u1ed1. T\u1eeb \u0111\u00f3 t\u00ecm \u0111\u01b0\u1ee3c c\u00e1c s\u1ed1 c\u00f2n thi\u1ebfu trong d\u00e3y s\u1ed1. - M\u1ed9t s\u1ed1 d\u1ea1ng quy lu\u1eadt trong d\u00e3y s\u1ed1: + D\u00e3y s\u1ed1 c\u00e1ch \u0111\u1ec1u: Hai s\u1ed1 li\u1ec1n k\u1ec1 nhau h\u01a1n k\u00e9m nhau m\u1ed9t s\u1ed1 \u0111\u01a1n v\u1ecb. + D\u00e3y s\u1ed1 c\u00f3 s\u1ed1 sau b\u1eb1ng t\u1ed5ng hai s\u1ed1 tr\u01b0\u1edbc. + D\u00e3y s\u1ed1 c\u00f3 quy lu\u1eadt l\u00e0 d\u00e3y s\u1ed1 ph\u1ee5: M\u1ed1i quan h\u1ec7 gi\u1eefa c\u00e1c s\u1ed1 h\u1ea1ng t\u1ea1o th\u00e0nh m\u1ed9t d\u00e3y s\u1ed1 c\u00f3 quy lu\u1eadt. V\u00ed d\u1ee5: Cho d\u00e3y s\u1ed1 \u0110i\u1ec1n v\u00e0o ch\u1ed7 tr\u1ed1ng s\u1ed1 h\u1ea1ng ti\u1ebfp theo c\u1ee7a d\u00e3y s\u1ed1. Gi\u1ea3i Ta th\u1ea5y: 4 + 1 = 5; 5 + 2 = 7; 7 + 3 = 10; 10 + 4 = 14; . . . V\u1eady quy lu\u1eadt c\u1ee7a d\u00e3y s\u1ed1 l\u00e0 s\u1ed1 sau s\u1ebd b\u1eb1ng s\u1ed1 tr\u01b0\u1edbc c\u1ed9ng v\u1edbi s\u1ed1 th\u1ee9 t\u1ef1 c\u1ee7a s\u1ed1 \u0111\u00f3. S\u1ed1 25 l\u00e0 s\u1ed1 th\u1ee9 7 trong d\u00e3y s\u1ed1, v\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n = 25 + 7 = 32 4. \u0110\u1ebfm h\u00ecnh, \u0111\u1ebfm \u0111o\u1ea1n th\u1eb3ng - V\u1edbi d\u1ebfm h\u00ecnh: \u0110\u00e1nh s\u1ed1 th\u1ee9 t\u1ef1 cho c\u00e1c h\u00ecnh nh\u1ecf. Sau \u0111\u00f3 \u0111\u1ebfm s\u1ed1 h\u00ecnh \u0111\u01a1n, ti\u1ebfp \u0111\u1ebfn l\u00e0 \u0111\u1ebfm c\u00e1c h\u00ecnh \u0111\u01b0\u1ee3c gh\u00e9p t\u1eeb 2, 3, 4, 5, \u2026 h\u00ecnh nh\u1ecf. R\u1ed3i c\u1ed9ng l\u1ea1i. \u00e0V\u00ed d\u1ee5: C\u00f3 bao nhi\u00eau h\u00ecnh tam gi\u00e1c trong h\u00ecnh sau? Gi\u1ea3i 93","1001 B\u00c0I TO\u00c1N T\u01af DUY - V\u1edbi d\u1ebfm \u0111o\u1ea1n th\u1eb3ng: C\u1ee9 hai \u0111i\u1ec3m kh\u00e1c nhau n\u1ed1i v\u1edbi nhau s\u1ebd t\u1ea1o th\u00e0nh m\u1ed9t \u0111o\u1ea1n th\u1eb3ng. \u00e0V\u00ed d\u1ee5: C\u00f3 bao nhi\u00eau \u0111o\u1ea1n th\u1eb3ng trong h\u00ecnh d\u01b0\u1edbi \u0111\u00e2y? Gi\u1ea3i 5. B\u00e0i to\u00e1n suy lu\u1eadn - L\u1eadp b\u1ea3ng suy lu\u1eadn \u0111\u1ec3 gi\u1ea3i c\u00e1c b\u00e0i to\u00e1n. \u00e0V\u00ed d\u1ee5: Trong gi\u1edd th\u1ec3 d\u1ee5c, 4 b\u1ea1n Jenny, Andy, Jack v\u00e0 Mary c\u00f9ng x\u1ebfp m\u1ed9t h\u00e0ng d\u1ecdc. Bi\u1ebft r\u1eb1ng, Andy \u0111\u1ee9ng th\u1ee9 ba trong h\u00e0ng, Jenny \u0111\u1ee9ng sau Mary, v\u00e0 Jack \u0111\u1ee9ng sau Andy. T\u00ecm v\u1ecb tr\u00ed c\u1ee7a t\u1eebng b\u1ea1n \u0111\u1ee9ng trong h\u00e0ng. Gi\u1ea3i 94","B\u1ed9 c\u00e2u h\u1ecfi tr\u1eafc nghi\u1ec7m C\u00e2u 1: Ch\u1ecdn c\u00e1ch chia \u0111\u1ec1u 6 qu\u1ea3 cherry cho 2 b\u1ea1n: C\u00e2u 2: Ch\u1ecdn ph\u00e9p t\u00ednh \u0111\u00fang: 10 qu\u1ea3 t\u00e1o chia th\u00e0nh 5 ph\u1ea7n b\u1eb1ng nhau? C\u00e2u 3: 8 c\u00e1i b\u00e1nh chia \u0111\u1ec1u cho 3 b\u1ea1n th\u00ec c\u00f2n d\u01b0 l\u1ea1i bao nhi\u00eau c\u00e1i b\u00e1nh? App HOC247 Kids 95 kids.hoc247.vn","C\u00e2u 4: 19 c\u00e1i b\u00e1nh chia \u0111\u1ec1u cho 5 \u0111\u0129a. H\u1ecfi c\u00f2n d\u01b0 l\u1ea1i bao nhi\u00eau c\u00e1i b\u00e1nh? C\u00e2u 5: V\u00e0o m\u1ed9t n\u0103m n\u00e0o \u0111\u00f3, ng\u00e0y 1 th\u00e1ng T\u01b0 l\u00e0 ng\u00e0y Ch\u1ee7 nh\u1eadt. H\u1ecfi ng\u00e0y 25 th\u00e1ng T\u01b0 c\u00f9ng n\u0103m l\u00e0 th\u1ee9 m\u1ea5y trong tu\u1ea7n? C\u00e2u 6: Ch\u1ecdn ph\u00e9p t\u00ednh \u0111\u00fang: 12 c\u00e1i b\u00e1nh chia \u0111\u1ec1u cho 6 b\u1ea1n. M\u1ed7i b\u1ea1n c\u00f3 bao nhi\u00eau c\u00e1i b\u00e1nh? C\u00e2u 7: Ch\u1eadu hoa \u0111\u1ea7u ti\u00ean l\u00e0 hoa tulip v\u00e0ng, k\u1ebf ti\u1ebfp l\u00e0 ch\u1eadu hoa tulip \u0111\u1ecf. Ch\u1eadu hoa tulip v\u00e0ng v\u00e0 ch\u1eadu tulip \u0111\u1ecf \u0111\u1eb7t xen k\u1ebd nhau. H\u1ecfi ch\u1eadu hoa th\u1ee9 11 l\u00e0 ch\u1eadu hoa m\u00e0u g\u00ec? App HOC247 Kids 96 kids.hoc247.vn","C\u00e2u 8: Nh\u00e0 b\u00e1c Lan c\u00f3 nu\u00f4i s\u1ed1 b\u00f2 v\u00e0 s\u1ed1 tr\u00e2u b\u1eb1ng nhau. B\u00e1c \u0111\u1ebfm \u0111\u01b0\u1ee3c s\u1ed1 t\u1ea5t c\u1ea3 48 c\u00e1i ch\u00e2n. H\u1ecfi c\u00f3 m\u1ea5y con b\u00f2 v\u00e0 m\u1ea5y con tr\u00e2u? C\u00e2u 9: Lan r\u1ea5t th\u00edch \u0111\u1ed9ng v\u1eadt, \u1edf nh\u00e0 Lan c\u00f3 r\u1ea5t nhi\u1ec1u m\u00e8o v\u00e0 ch\u00f3. Bi\u1ebft r\u1eb1ng t\u1ed5ng s\u1ed1 ch\u00e2n m\u00e8o v\u00e0 ch\u00f3 \u1edf nh\u00e0 Lan l\u00e0 24 ch\u00e2n, v\u00e0 s\u1ed1 m\u00e8o b\u1eb1ng s\u1ed1 ch\u00f3. H\u1ecfi nh\u00e0 Lan nu\u00f4i bao nhi\u00eau con ch\u00f3 v\u00e0 bao nhi\u00eau con m\u00e8o? C\u00e2u 10: M\u1eb9 \u0111i ch\u1ee3 mua cho Anan m\u1ed9t s\u1ed1 \u00e1o qu\u1ea7n \u0111\u1ec3 v\u00e0o n\u0103m h\u1ecdc m\u1edbi, bi\u1ebft 1 c\u00e1i \u00e1o c\u00f3 gi\u00e1 l\u00e0 7$ v\u00e0 1 c\u00e1i qu\u1ea7n c\u00f3 gi\u00e1 l\u00e0 9$. M\u1eb9 mua t\u1ea5t c\u1ea3 4 \u00e1o v\u00e0 qu\u1ea7n. Bi\u1ebft m\u1eb9 ph\u1ea3i tr\u1ea3 32$ cho c\u1ea3 \u00e1o v\u00e0 qu\u1ea7n. H\u1ecfi m\u1eb9 mua bao nhi\u00eau c\u00e1i \u00e1o v\u00e0 bao nhi\u00eau c\u00e1i qu\u1ea7n? App HOC247 Kids 97 kids.hoc247.vn","C\u00e2u 11: Ly Ly mua m\u1ed9t s\u1ed1 s\u1ed5 v\u00e0 b\u00fat ch\u00ec, m\u1ed9t c\u00e2y b\u00fat ch\u00ec c\u00f3 gi\u00e1 6$ v\u00e0 m\u1ed9t cu\u1ed1n s\u1ed5 c\u00f3 gi\u00e1 7$. Ly Ly ph\u1ea3i tr\u1ea3 h\u1ebft 40$ cho t\u1ea5t c\u1ea3 6 cu\u1ed1n s\u1ed5 v\u00e0 b\u00fat ch\u00ec. H\u1ecfi Ly Ly \u0111\u00e3 mua bao nhi\u00eau cu\u1ed1n s\u1ed5 v\u00e0 bao nhi\u00eau c\u00e2y b\u00fat ch\u00ec? C\u00e2u 12: M\u1ed9t chi\u1ebfc xe \u0111\u1ea1p c\u00f3 3 b\u00e1nh, xe \u0111\u1ea1p b\u00ecnh th\u01b0\u1eddng c\u00f3 2 b\u00e1nh, 10 xe c\u00f3 t\u1ea5t c\u1ea3 24 b\u00e1nh xe. H\u1ecfi c\u00f3 bao nhi\u00eau xe \u0111\u1ea1p 2 b\u00e1nh v\u00e0 bao nhi\u00eau xe \u0111\u1ea1p 3 b\u00e1nh? C\u00e2u 13: Trong b\u00e3i gi\u1eef xe, c\u00f3 10 xe c\u1ea3 xe \u00f4 t\u00f4 v\u00e0 xe m\u00e1y. Bi\u1ebft t\u1ed5ng c\u1ed9ng c\u00f3 30 b\u00e1nh xe. H\u1ecfi c\u00f3 bao nhi\u00eau xe \u00f4 t\u00f4, bao nhi\u00eau xe m\u00e1y? C\u00e2u 14: C\u00f3 t\u1ea5t c\u1ea3 4 con nh\u1ec7n v\u00e0 chu\u1ed3n chu\u1ed3n v\u1edbi t\u1ed5ng c\u1ed9ng 30 ch\u00e2n. T\u00ecm s\u1ed1 nh\u1ec7n v\u00e0 chu\u1ed3n chu\u1ed3n. App HOC247 Kids 98 kids.hoc247.vn","C\u00e2u 15: T\u00ecm s\u1ed1 c\u00f2n thi\u1ebfu trong h\u00ecnh sau: C\u00e2u 16: T\u00ecm s\u1ed1 c\u00f2n thi\u1ebfu trong d\u00e3y s\u1ed1 sau: 4; 8; 12; 16; 20; ... C\u00e2u 17: T\u00ecm s\u1ed1 c\u00f2n thi\u1ebfu trong d\u00e3y s\u1ed1 sau: 2; 2; 4; 6; 10; 16; ... App HOC247 Kids 99 kids.hoc247.vn","C\u00e2u 18: T\u00ecm s\u1ed1 c\u00f2n thi\u1ebfu trong h\u00ecnh d\u01b0\u1edbi \u0111\u00e2y: C\u00e2u 19: T\u00ecm s\u1ed1 c\u00f2n thi\u1ebfu trong h\u00ecnh d\u01b0\u1edbi \u0111\u00e2y: C\u00e2u 20: T\u00ecm s\u1ed1 c\u00f2n thi\u1ebfu trong d\u00e3y s\u1ed1 sau: C\u00e2u 21: T\u00ecm s\u1ed1 c\u00f2n thi\u1ebfu trong h\u00ecnh d\u01b0\u1edbi \u0111\u00e2y: App HOC247 Kids 100 kids.hoc247.vn"]