\n| 1. Ph\u00e2n s\u1ed1, H\u1ed7n s\u1ed1 & S\u1ed1 th\u1eadp ph\u00e2n<\/td>\n | \u0110\u1ecdc, vi\u1ebft s\u1ed1 th\u1eadp ph\u00e2n; x\u00e1c \u0111\u1ecbnh gi\u00e1 tr\u1ecb ch\u1eef s\u1ed1 theo h\u00e0ng; nh\u1eadn di\u1ec7n ph\u00e2n s\u1ed1 th\u1eadp ph\u00e2n (2,5 \u0111i\u1ec3m).<\/td>\n | So s\u00e1nh s\u1ed1 th\u1eadp ph\u00e2n; \u0111\u1eb7t t\u00ednh c\u1ed9ng, tr\u1eeb, nh\u00e2n s\u1ed1 th\u1eadp ph\u00e2n v\u00e0 t\u00ednh to\u00e1n v\u1edbi ph\u00e2n s\u1ed1\/h\u1ed7n s\u1ed1 (2,0 \u0111i\u1ec3m).<\/td>\n | T\u00ednh b\u1eb1ng c\u00e1ch thu\u1eadn ti\u1ec7n nh\u1ea5t v\u1edbi bi\u1ec3u th\u1ee9c s\u1ed1 th\u1eadp ph\u00e2n ho\u1eb7c t\u00ecm x n\u00e2ng cao (1,0 \u0111i\u1ec3m).<\/td>\n | 5,5 \u0111i\u1ec3m<\/td>\n<\/tr>\n |
\n| 2. \u0110\u1ea1i l\u01b0\u1ee3ng & \u0110\u1ed5i \u0111\u01a1n v\u1ecb \u0111o<\/td>\n | Nh\u1eadn bi\u1ebft m\u1ed1i quan h\u1ec7 gi\u1eefa c\u00e1c \u0111\u01a1n v\u1ecb \u0111o \u0111\u1ed9 d\u00e0i, kh\u1ed1i l\u01b0\u1ee3ng, h\u00e9c-ta (1,0 \u0111i\u1ec3m).<\/td>\n | Vi\u1ebft s\u1ed1 \u0111o \u0111\u1ed9 d\u00e0i, kh\u1ed1i l\u01b0\u1ee3ng, di\u1ec7n t\u00edch (m2<\/sup>, ha, km2<\/sup>) d\u01b0\u1edbi d\u1ea1ng s\u1ed1 th\u1eadp ph\u00e2n (1,0 \u0111i\u1ec3m).<\/td>\n| –<\/td>\n | 2,0 \u0111i\u1ec3m<\/td>\n<\/tr>\n | \n| 3. Gi\u1ea3i to\u00e1n c\u00f3 l\u1eddi v\u0103n & H\u00ecnh h\u1ecdc<\/td>\n | Nh\u1eadn bi\u1ebft c\u00f4ng th\u1ee9c chu vi, di\u1ec7n t\u00edch h\u00ecnh ch\u1eef nh\u1eadt, h\u00ecnh vu\u00f4ng (0,5 \u0111i\u1ec3m).<\/td>\n | Gi\u1ea3i b\u00e0i to\u00e1n v\u1ec1 t\u1ec9 s\u1ed1 ho\u1eb7c r\u00fat v\u1ec1 \u0111\u01a1n v\u1ecb c\u01a1 b\u1ea3n (1,0 \u0111i\u1ec3m).<\/td>\n | B\u00e0i to\u00e1n th\u1ef1c t\u1ebf k\u1ebft h\u1ee3p t\u00ednh di\u1ec7n t\u00edch th\u1eeda ru\u1ed9ng v\u00e0 n\u0103ng su\u1ea5t thu ho\u1ea1ch (1,0 \u0111i\u1ec3m).<\/td>\n | 2,5 \u0111i\u1ec3m<\/td>\n<\/tr>\n | \n| T\u1ed4NG T\u1ef6 L\u1ec6 \/ \u0110I\u1ec2M S\u1ed0<\/td>\n | 4,0 \u0111i\u1ec3m (40%)<\/td>\n | 4,0 \u0111i\u1ec3m (40%)<\/td>\n | 2,0 \u0111i\u1ec3m (20%)<\/td>\n | 10,0 \u0111i\u1ec3m<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n <\/p>\n \n Ph\u1ea7n I: Tr\u1ecdng T\u00e2m S\u1ed1 H\u1ecdc \u2013 Ph\u00e2n S\u1ed1 V\u00e0 S\u1ed1 Th\u1eadp Ph\u00e2n<\/h2>\n<\/div>\n<\/p>\n S\u1ed1 h\u1ecdc l\u00e0 ph\u1ea7n chi\u1ebfm nhi\u1ec1u \u0111i\u1ec3m nh\u1ea5t trong \u0111\u1ec1, v\u00ec v\u1eady \u0111\u00e2y c\u0169ng l\u00e0 ph\u1ea7n tr\u1ecdng t\u00e2m c\u1ee7a \u0111\u1ec1 c\u01b0\u01a1ng \u00f4n t\u1eadp gi\u1eefa k\u00ec 1 To\u00e1n 5<\/strong>. Con c\u1ea7n n\u1eafm ch\u1eafc 7 ch\u1ee7 \u0111\u1ec1 d\u01b0\u1edbi \u0111\u00e2y, \u0111i t\u1eeb ph\u00e2n s\u1ed1, h\u1ed7n s\u1ed1 \u0111\u1ebfn c\u00e1c ph\u00e9p t\u00ednh v\u1edbi s\u1ed1 th\u1eadp ph\u00e2n.<\/p>\n\u00d4n t\u1eadp ph\u00e2n s\u1ed1<\/h2>\nT\u00ednh ch\u1ea5t c\u01a1 b\u1ea3n, r\u00fat g\u1ecdn, quy \u0111\u1ed3ng v\u00e0 so s\u00e1nh ph\u00e2n s\u1ed1<\/h3>\n\n- T\u00ednh ch\u1ea5t c\u01a1 b\u1ea3n:<\/strong> Khi nh\u00e2n ho\u1eb7c chia c\u1ea3 t\u1eed s\u1ed1 v\u00e0 m\u1eabu s\u1ed1 c\u1ee7a m\u1ed9t ph\u00e2n s\u1ed1 v\u1edbi c\u00f9ng m\u1ed9t s\u1ed1 t\u1ef1 nhi\u00ean kh\u00e1c 0 th\u00ec ta \u0111\u01b0\u1ee3c m\u1ed9t ph\u00e2n s\u1ed1 m\u1edbi b\u1eb1ng ph\u00e2n s\u1ed1 \u0111\u00e3 cho.<\/li>\n
- R\u00fat g\u1ecdn ph\u00e2n s\u1ed1:<\/strong> Chia c\u1ea3 t\u1eed v\u00e0 m\u1eabu cho c\u00f9ng m\u1ed9t s\u1ed1 t\u1ef1 nhi\u00ean l\u1edbn h\u01a1n 1 cho \u0111\u1ebfn khi nh\u1eadn \u0111\u01b0\u1ee3c ph\u00e2n s\u1ed1 t\u1ed1i gi\u1ea3n<\/strong> (kh\u00f4ng th\u1ec3 r\u00fat g\u1ecdn \u0111\u01b0\u1ee3c n\u1eefa).<\/li>\n
- Quy \u0111\u1ed3ng m\u1eabu s\u1ed1:<\/strong> \u0110\u01b0a c\u00e1c ph\u00e2n s\u1ed1 kh\u00e1c m\u1eabu v\u1ec1 c\u00f9ng m\u1ed9t m\u1eabu s\u1ed1 chung (\u01b0u ti\u00ean ch\u1ecdn m\u1eabu s\u1ed1 chung nh\u1ecf nh\u1ea5t n\u1ebfu m\u1eabu s\u1ed1 n\u00e0y chia h\u1ebft cho m\u1eabu s\u1ed1 kia).<\/li>\n
- So s\u00e1nh hai ph\u00e2n s\u1ed1:<\/strong>\n
\n- C\u00f9ng m\u1eabu s\u1ed1:<\/em> Ph\u00e2n s\u1ed1 n\u00e0o c\u00f3 t\u1eed s\u1ed1 l\u1edbn h\u01a1n th\u00ec l\u1edbn h\u01a1n.<\/li>\n
- C\u00f9ng t\u1eed s\u1ed1:<\/em> Ph\u00e2n s\u1ed1 n\u00e0o c\u00f3 m\u1eabu s\u1ed1 b\u00e9 h\u01a1n th\u00ec l\u1edbn h\u01a1n.<\/li>\n
- So s\u00e1nh v\u1edbi 1:<\/em> T\u1eed < M\u1eabu \u21d2 Ph\u00e2n s\u1ed1 < 1; T\u1eed > M\u1eabu \u21d2 Ph\u00e2n s\u1ed1 > 1; T\u1eed = M\u1eabu \u21d2 Ph\u00e2n s\u1ed1 = 1.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
B\u1ed1n ph\u00e9p t\u00ednh v\u1edbi ph\u00e2n s\u1ed1 & l\u1ed7i sai th\u01b0\u1eddng g\u1eb7p<\/h3>\n\n- Ph\u00e9p c\u1ed9ng v\u00e0 ph\u00e9p tr\u1eeb:<\/strong> Ph\u1ea3i \u0111\u01b0a v\u1ec1 c\u00f9ng m\u1eabu s\u1ed1 r\u1ed3i c\u1ed9ng (ho\u1eb7c tr\u1eeb) hai t\u1eed s\u1ed1 v\u00e0 gi\u1eef nguy\u00ean m\u1eabu s\u1ed1<\/strong>.<\/li>\n
- Ph\u00e9p nh\u00e2n:<\/strong> L\u1ea5y t\u1eed s\u1ed1 nh\u00e2n v\u1edbi t\u1eed s\u1ed1, m\u1eabu s\u1ed1 nh\u00e2n v\u1edbi m\u1eabu s\u1ed1:
(a\/b) \u00d7 (c\/d) = (a \u00d7 c) \/ (b \u00d7 d)<\/code>.<\/li>\n- Ph\u00e9p chia:<\/strong> L\u1ea5y ph\u00e2n s\u1ed1 th\u1ee9 nh\u1ea5t nh\u00e2n v\u1edbi ph\u00e2n s\u1ed1 th\u1ee9 hai \u0111\u1ea3o ng\u01b0\u1ee3c<\/strong>:
(a\/b) : (c\/d) = (a\/b) \u00d7 (d\/c)<\/code>.<\/li>\n- L\u1ed7i sai th\u01b0\u1eddng g\u1eb7p:<\/strong> H\u1ecdc sinh hay c\u1ed9ng nh\u1ea7m c\u1ea3 t\u1eed v\u1edbi t\u1eed, m\u1eabu v\u1edbi m\u1eabu (v\u00ed d\u1ee5 sai:
1\/2 + 1\/3 = 2\/5<\/code>); ho\u1eb7c sau khi t\u00ednh xong qu\u00ean r\u00fat g\u1ecdn k\u1ebft qu\u1ea3 cu\u1ed1i c\u00f9ng v\u1ec1 ph\u00e2n s\u1ed1 t\u1ed1i gi\u1ea3n d\u1eabn \u0111\u1ebfn b\u1ecb tr\u1eeb 0,25 \u0111i\u1ec3m tr\u00ecnh b\u00e0y.<\/li>\n<\/ul>\n\n V\u00ed d\u1ee5 m\u1eabu 1: T\u00ednh gi\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c ph\u00e2n s\u1ed1<\/p>\n \u0110\u1ec1 b\u00e0i:<\/strong> T\u00ednh: 3\/5 + 2\/5 \u00d7 5\/6<\/code><\/p>\nL\u1eddi gi\u1ea3i:<\/strong> Th\u1ef1c hi\u1ec7n nh\u00e2n chia tr\u01b0\u1edbc, c\u1ed9ng tr\u1eeb sau:
\n3\/5 + 2\/5 \u00d7 5\/6 = 3\/5 + (2 \u00d7 5) \/ (5 \u00d7 6) = 3\/5 + 1\/3 = 9\/15 + 5\/15 = 14\/15<\/strong><\/code>.<\/p>\n<\/div>\n<\/p>\n H\u1ed7n s\u1ed1<\/h2>\nC\u1ea5u t\u1ea1o c\u1ee7a h\u1ed7n s\u1ed1<\/h3>\n\n- M\u1ed7i h\u1ed7n s\u1ed1 \u0111\u1ec1u g\u1ed3m hai ph\u1ea7n gh\u00e9p l\u1ea1i: Ph\u1ea7n nguy\u00ean<\/strong> (\u0111\u1ee9ng tr\u01b0\u1edbc) v\u00e0 Ph\u1ea7n ph\u00e2n s\u1ed1<\/strong> (\u0111\u1ee9ng sau).<\/li>\n
- Quy t\u1eafc b\u1eaft bu\u1ed9c c\u1ea7n nh\u1edb:<\/strong> Ph\u1ea7n ph\u00e2n s\u1ed1 c\u1ee7a h\u1ed7n s\u1ed1 bao gi\u1edd c\u0169ng b\u00e9 h\u01a1n 1<\/strong> (t\u1eed s\u1ed1 lu\u00f4n b\u00e9 h\u01a1n m\u1eabu s\u1ed1). V\u00ed d\u1ee5:
2 v\u00e0 3\/4<\/code> l\u00e0 h\u1ed7n s\u1ed1 \u0111\u00fang; nh\u01b0ng 2 v\u00e0 5\/4<\/code> l\u00e0 vi\u1ebft sai v\u00ec 5\/4 > 1<\/code>.<\/li>\n<\/ul>\nC\u00e1ch \u0111\u1ed5i h\u1ed7n s\u1ed1 ra ph\u00e2n s\u1ed1 v\u00e0 th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh<\/h3>\n\n- C\u00f4ng th\u1ee9c \u0111\u1ed5i h\u1ed7n s\u1ed1 ra ph\u00e2n s\u1ed1:<\/strong>\n
T\u1eed s\u1ed1 m\u1edbi = (Ph\u1ea7n nguy\u00ean \u00d7 M\u1eabu s\u1ed1) + T\u1eed s\u1ed1 c\u0169 \u00a0|\u00a0 Gi\u1eef nguy\u00ean M\u1eabu s\u1ed1<\/div>\n<\/li>\n - T\u00ednh to\u00e1n v\u1edbi h\u1ed7n s\u1ed1:<\/strong> Khi th\u1ef1c hi\u1ec7n ph\u00e9p c\u1ed9ng, tr\u1eeb, nh\u00e2n, chia c\u00f3 ch\u1ee9a h\u1ed7n s\u1ed1, c\u00e1ch an to\u00e0n nh\u1ea5t l\u00e0 chuy\u1ec3n t\u1ea5t c\u1ea3 c\u00e1c h\u1ed7n s\u1ed1 v\u1ec1 d\u1ea1ng ph\u00e2n s\u1ed1 r\u1ed3i t\u00ednh nh\u01b0 b\u00ecnh th\u01b0\u1eddng.<\/li>\n<\/ul>\n
\n V\u00ed d\u1ee5 m\u1eabu 2: Chuy\u1ec3n h\u1ed7n s\u1ed1 th\u00e0nh ph\u00e2n s\u1ed1 r\u1ed3i t\u00ednh<\/p>\n \u0110\u1ec1 b\u00e0i:<\/strong> T\u00ednh: (2 v\u00e0 1\/3) + (1 v\u00e0 1\/2)<\/code><\/p>\nL\u1eddi gi\u1ea3i:<\/strong>
\n\u2022 \u0110\u1ed5i h\u1ed7n s\u1ed1: 2 v\u00e0 1\/3 = (2 \u00d7 3 + 1) \/ 3 = 7\/3<\/code> \u00a0;\u00a0 1 v\u00e0 1\/2 = (1 \u00d7 2 + 1) \/ 2 = 3\/2<\/code>.
\n\u2022 Th\u1ef1c hi\u1ec7n ph\u00e9p c\u1ed9ng: 7\/3 + 3\/2 = 14\/6 + 9\/6 = 23\/6<\/strong><\/code>.<\/p>\n<\/div>\n<\/p>\n Ph\u00e2n s\u1ed1 th\u1eadp ph\u00e2n<\/h2>\n\u0110\u1ecbnh ngh\u0129a nh\u1eadn di\u1ec7n<\/h3>\nPh\u00e2n s\u1ed1 th\u1eadp ph\u00e2n<\/strong> l\u00e0 c\u00e1c ph\u00e2n s\u1ed1 c\u00f3 m\u1eabu s\u1ed1 l\u00e0 10; 100; 1000; 10 000; …<\/strong> (V\u00ed d\u1ee5: 7\/10<\/code>, 35\/100<\/code>, 129\/1000<\/code>).<\/p>\nC\u00e1ch \u0111\u01b0a m\u1ed9t ph\u00e2n s\u1ed1 v\u1ec1 ph\u00e2n s\u1ed1 th\u1eadp ph\u00e2n<\/h3>\nTa nh\u00e2n (ho\u1eb7c chia) c\u1ea3 t\u1eed s\u1ed1 v\u00e0 m\u1eabu s\u1ed1 c\u1ee7a ph\u00e2n s\u1ed1 \u0111\u00f3 v\u1edbi m\u1ed9t s\u1ed1 t\u1ef1 nhi\u00ean th\u00edch h\u1ee3p \u0111\u1ec3 m\u1eabu s\u1ed1 m\u1edbi tr\u1edf th\u00e0nh 10, 100, 1000… H\u1ecdc sinh l\u1edbp 5 c\u1ea7n thu\u1ed9c l\u00f2ng “3 c\u1eb7p s\u1ed1 v\u00e0ng”<\/strong> sau \u0111\u00e2y \u0111\u1ec3 bi\u1ebfn \u0111\u1ed5i si\u00eau t\u1ed1c:<\/p>\n\n- G\u1eb7p m\u1eabu s\u1ed1 l\u00e0 2 ho\u1eb7c 5<\/strong> \u21d2 Nh\u00e2n v\u1edbi 5 ho\u1eb7c 2<\/strong> \u0111\u1ec3 \u0111\u01b0a v\u1ec1 m\u1eabu s\u1ed1 10<\/strong> (V\u00ed d\u1ee5:
2\/5 = (2 \u00d7 2) \/ (5 \u00d7 2) = 4\/10<\/code>).<\/li>\n- G\u1eb7p m\u1eabu s\u1ed1 l\u00e0 4 ho\u1eb7c 25<\/strong> \u21d2 Nh\u00e2n v\u1edbi 25 ho\u1eb7c 4<\/strong> \u0111\u1ec3 \u0111\u01b0a v\u1ec1 m\u1eabu s\u1ed1 100<\/strong> (V\u00ed d\u1ee5:
3\/4 = (3 \u00d7 25) \/ (4 \u00d7 25) = 75\/100<\/code>).<\/li>\n- G\u1eb7p m\u1eabu s\u1ed1 l\u00e0 8 ho\u1eb7c 125<\/strong> \u21d2 Nh\u00e2n v\u1edbi 125 ho\u1eb7c 8<\/strong> \u0111\u1ec3 \u0111\u01b0a v\u1ec1 m\u1eabu s\u1ed1 1000<\/strong> (V\u00ed d\u1ee5:
1\/8 = (1 \u00d7 125) \/ (8 \u00d7 125) = 125\/1000<\/code>).<\/li>\n<\/ul>\n\n V\u00ed d\u1ee5 m\u1eabu 3: Bi\u1ebfn \u0111\u1ed5i ph\u00e2n s\u1ed1 th\u00e0nh ph\u00e2n s\u1ed1 th\u1eadp ph\u00e2n<\/p>\n \u0110\u1ec1 b\u00e0i:<\/strong> Vi\u1ebft c\u00e1c ph\u00e2n s\u1ed1 9\/25<\/code> v\u00e0 18\/30<\/code> th\u00e0nh ph\u00e2n s\u1ed1 th\u1eadp ph\u00e2n.<\/p>\nL\u1eddi gi\u1ea3i:<\/strong>
\n\u2022 9\/25 = (9 \u00d7 4) \/ (25 \u00d7 4) = 36\/100<\/strong><\/code> (Nh\u00e2n c\u1ea3 t\u1eed v\u00e0 m\u1eabu v\u1edbi 4).
\n\u2022 18\/30 = (18 : 3) \/ (30 : 3) = 6\/10<\/strong><\/code> (Chia r\u00fat g\u1ecdn c\u1ea3 t\u1eed v\u00e0 m\u1eabu cho 3 \u0111\u1ec3 \u0111\u01b0a v\u1ec1 m\u1eabu 10).<\/p>\n<\/div>\n<\/p>\n S\u1ed1 th\u1eadp ph\u00e2n<\/h2>\nC\u1ea5u t\u1ea1o v\u00e0 gi\u00e1 tr\u1ecb c\u00e1c h\u00e0ng c\u1ee7a s\u1ed1 th\u1eadp ph\u00e2n<\/h3>\n\n- M\u1ed7i s\u1ed1 th\u1eadp ph\u00e2n g\u1ed3m hai ph\u1ea7n ng\u0103n c\u00e1ch nhau b\u1edfi d\u1ea5u ph\u1ea9y (,)<\/strong>:\n
\n- Ph\u1ea7n nguy\u00ean:<\/strong> Nh\u1eefng ch\u1eef s\u1ed1 n\u1eb1m b\u00ean tr\u00e1i d\u1ea5u ph\u1ea9y (h\u00e0ng tr\u0103m, h\u00e0ng ch\u1ee5c, h\u00e0ng \u0111\u01a1n v\u1ecb…).<\/li>\n
- Ph\u1ea7n th\u1eadp ph\u00e2n:<\/strong> Nh\u1eefng ch\u1eef s\u1ed1 n\u1eb1m b\u00ean ph\u1ea3i d\u1ea5u ph\u1ea9y.<\/li>\n<\/ul>\n<\/li>\n
- Th\u1ee9 t\u1ef1 c\u00e1c h\u00e0ng \u1edf ph\u1ea7n th\u1eadp ph\u00e2n (t\u00ednh t\u1eeb d\u1ea5u ph\u1ea9y sang b\u00ean ph\u1ea3i):<\/strong>\n
\n- Ch\u1eef s\u1ed1 th\u1ee9 nh\u1ea5t sau d\u1ea5u ph\u1ea9y: H\u00e0ng ph\u1ea7n m\u01b0\u1eddi<\/strong> (gi\u00e1 tr\u1ecb b\u1eb1ng
1\/10<\/code>).<\/li>\n- Ch\u1eef s\u1ed1 th\u1ee9 hai sau d\u1ea5u ph\u1ea9y: H\u00e0ng ph\u1ea7n tr\u0103m<\/strong> (gi\u00e1 tr\u1ecb b\u1eb1ng
1\/100<\/code>).<\/li>\n- Ch\u1eef s\u1ed1 th\u1ee9 ba sau d\u1ea5u ph\u1ea9y: H\u00e0ng ph\u1ea7n ngh\u00ecn<\/strong> (gi\u00e1 tr\u1ecb b\u1eb1ng
1\/1000<\/code>).<\/li>\n<\/ul>\n<\/li>\n<\/ul>\nM\u1eb9o chuy\u1ec3n ph\u00e2n s\u1ed1 th\u1eadp ph\u00e2n & h\u1ed7n s\u1ed1 sang s\u1ed1 th\u1eadp ph\u00e2n<\/h3>\nQuy t\u1eafc \u0111\u1ebfm ch\u1eef s\u1ed1 0 \u1edf m\u1eabu s\u1ed1:<\/strong> M\u1eabu s\u1ed1 c\u1ee7a ph\u00e2n s\u1ed1 th\u1eadp ph\u00e2n c\u00f3 bao nhi\u00eau ch\u1eef s\u1ed1 0<\/strong> th\u00ec \u1edf ph\u1ea7n th\u1eadp ph\u00e2n c\u1ee7a s\u1ed1 th\u1eadp ph\u00e2n ph\u1ea3i c\u00f3 b\u1ea5y nhi\u00eau ch\u1eef s\u1ed1<\/strong> sau d\u1ea5u ph\u1ea9y (n\u1ebfu thi\u1ebfu ch\u1eef s\u1ed1 th\u00ec ph\u1ea3i vi\u1ebft th\u00eam ch\u1eef s\u1ed1 0 v\u00e0o ngay sau d\u1ea5u ph\u1ea9y):<\/p>\n\n7\/10 = 0,7<\/code> (M\u1eabu 10 c\u00f3 1 ch\u1eef s\u1ed1 0 \u2192 1 ch\u1eef s\u1ed1 sau d\u1ea5u ph\u1ea9y).<\/li>\n5\/100 = 0,05<\/code> (M\u1eabu 100 c\u00f3 2 ch\u1eef s\u1ed1 0 \u2192 2 ch\u1eef s\u1ed1 sau d\u1ea5u ph\u1ea9y, kh\u00f4ng \u0111\u01b0\u1ee3c vi\u1ebft nh\u1ea7m th\u00e0nh 0,5).<\/li>\n4 v\u00e0 25\/1000 = 4,025<\/code> (Ph\u1ea7n nguy\u00ean l\u00e0 4; m\u1eabu 1000 c\u00f3 3 ch\u1eef s\u1ed1 0 n\u00ean ph\u1ea7n th\u1eadp ph\u00e2n l\u00e0 025).<\/li>\n<\/ul>\n\n V\u00ed d\u1ee5 m\u1eabu 4: X\u00e1c \u0111\u1ecbnh gi\u00e1 tr\u1ecb ch\u1eef s\u1ed1 v\u00e0 vi\u1ebft s\u1ed1 th\u1eadp ph\u00e2n<\/p>\n \u0110\u1ec1 b\u00e0i:<\/strong> Cho s\u1ed1 th\u1eadp ph\u00e2n 45,308<\/strong>. H\u00e3y n\u00eau gi\u00e1 tr\u1ecb c\u1ee7a ch\u1eef s\u1ed1 3, ch\u1eef s\u1ed1 8 v\u00e0 vi\u1ebft h\u1ed7n s\u1ed1 12 v\u00e0 7\/100<\/code> d\u01b0\u1edbi d\u1ea1ng s\u1ed1 th\u1eadp ph\u00e2n.<\/p>\nL\u1eddi gi\u1ea3i:<\/strong>
\n\u2022 Trong s\u1ed1 45,308<\/strong>: Ch\u1eef s\u1ed1 3<\/strong> \u0111\u1ee9ng \u1edf h\u00e0ng ph\u1ea7n m\u01b0\u1eddi c\u00f3 gi\u00e1 tr\u1ecb l\u00e0 3\/10<\/code> (ho\u1eb7c 0,3<\/code>); ch\u1eef s\u1ed1 8<\/strong> \u0111\u1ee9ng \u1edf h\u00e0ng ph\u1ea7n ngh\u00ecn c\u00f3 gi\u00e1 tr\u1ecb l\u00e0 8\/1000<\/code> (ho\u1eb7c 0,008<\/code>).
\n\u2022 H\u1ed7n s\u1ed1 12 v\u00e0 7\/100<\/code> c\u00f3 ph\u1ea7n nguy\u00ean l\u00e0 12, m\u1eabu s\u1ed1 100 c\u00f3 2 ch\u1eef s\u1ed1 0 n\u00ean vi\u1ebft th\u00e0nh s\u1ed1 th\u1eadp ph\u00e2n l\u00e0: 12,07<\/strong>.<\/p>\n<\/div>\n<\/div>\n<\/p>\n <\/p>\n \n <\/p>\n So s\u00e1nh s\u1ed1 th\u1eadp ph\u00e2n<\/h2>\nQuy t\u1eafc 2 b\u01b0\u1edbc so s\u00e1nh s\u1ed1 th\u1eadp ph\u00e2n<\/h3>\n\n- B\u01b0\u1edbc 1 (So s\u00e1nh ph\u1ea7n nguy\u00ean):<\/strong> So s\u00e1nh ph\u1ea7n nguy\u00ean c\u1ee7a hai s\u1ed1 nh\u01b0 so s\u00e1nh hai s\u1ed1 t\u1ef1 nhi\u00ean. S\u1ed1 n\u00e0o c\u00f3 ph\u1ea7n nguy\u00ean l\u1edbn h\u01a1n th\u00ec s\u1ed1 \u0111\u00f3 l\u1edbn h\u01a1n.<\/li>\n
- B\u01b0\u1edbc 2 (So s\u00e1nh ph\u1ea7n th\u1eadp ph\u00e2n):<\/strong> N\u1ebfu ph\u1ea7n nguy\u00ean b\u1eb1ng nhau, ta l\u1ea7n l\u01b0\u1ee3t so s\u00e1nh c\u00e1c ch\u1eef s\u1ed1 \u1edf c\u00f9ng m\u1ed9t h\u00e0ng \u1edf ph\u1ea7n th\u1eadp ph\u00e2n t\u1eeb tr\u00e1i sang ph\u1ea3i (h\u00e0ng ph\u1ea7n m\u01b0\u1eddi \u2192 h\u00e0ng ph\u1ea7n tr\u0103m \u2192 h\u00e0ng ph\u1ea7n ngh\u00ecn…). Ch\u1eef s\u1ed1 \u1edf h\u00e0ng n\u00e0o l\u1edbn h\u01a1n th\u00ec s\u1ed1 \u0111\u00f3 l\u1edbn h\u01a1n.<\/li>\n<\/ul>\n
C\u00e1c d\u1ea1ng b\u00e0i tr\u1ecdng t\u00e2m & t\u00ednh ch\u1ea5t quan tr\u1ecdng<\/h3>\n\n- S\u1ed1 th\u1eadp ph\u00e2n b\u1eb1ng nhau:<\/strong> N\u1ebfu vi\u1ebft th\u00eam ch\u1eef s\u1ed1
0<\/code> v\u00e0o b\u00ean ph\u1ea3i ph\u1ea7n th\u1eadp ph\u00e2n c\u1ee7a m\u1ed9t s\u1ed1 th\u1eadp ph\u00e2n th\u00ec \u0111\u01b0\u1ee3c m\u1ed9t s\u1ed1 th\u1eadp ph\u00e2n b\u1eb1ng n\u00f3 (V\u00ed d\u1ee5: 5,7 = 5,70 = 5,700<\/code>). Ng\u01b0\u1ee3c l\u1ea1i, n\u1ebfu b\u1ecf c\u00e1c ch\u1eef s\u1ed1 0<\/code> \u1edf t\u1eadn c\u00f9ng b\u00ean ph\u1ea3i ph\u1ea7n th\u1eadp ph\u00e2n th\u00ec \u0111\u01b0\u1ee3c m\u1ed9t s\u1ed1 th\u1eadp ph\u00e2n b\u1eb1ng n\u00f3.<\/li>\n- S\u1eafp x\u1ebfp th\u1ee9 t\u1ef1:<\/strong> D\u1ef1a v\u00e0o quy t\u1eafc so s\u00e1nh \u0111\u1ec3 s\u1eafp x\u1ebfp d\u00e3y s\u1ed1 theo th\u1ee9 t\u1ef1 t\u1eeb b\u00e9 \u0111\u1ebfn l\u1edbn ho\u1eb7c t\u1eeb l\u1edbn \u0111\u1ebfn b\u00e9.<\/li>\n
- T\u00ecm s\u1ed1 th\u1eadp ph\u00e2n x n\u1eb1m gi\u1eefa hai s\u1ed1:<\/strong> V\u00ed d\u1ee5 t\u00ecm s\u1ed1 th\u1eadp ph\u00e2n
x<\/code> sao cho 2,1 < x < 2,2<\/code>. Ta vi\u1ebft th\u00eam ch\u1eef s\u1ed1 0<\/code> v\u00e0o t\u1eadn c\u00f9ng ph\u1ea7n th\u1eadp ph\u00e2n \u0111\u1ec3 d\u1ec5 nh\u1eadn ra: 2,10 < x < 2,20<\/code>, t\u1eeb \u0111\u00f3 d\u1ec5 d\u00e0ng ch\u1ecdn c\u00e1c gi\u00e1 tr\u1ecb nh\u01b0 x = 2,11; 2,15; 2,19...<\/code><\/li>\n<\/ul>\n\n \u26a0\ufe0f L\u1ed7i sai th\u01b0\u1eddng g\u1eb7p khi so s\u00e1nh s\u1ed1 th\u1eadp ph\u00e2n:<\/p>\n \n- H\u1ecdc sinh hay nh\u00ecn v\u00e0o \u0111\u1ed9 d\u00e0i c\u1ee7a ph\u1ea7n th\u1eadp ph\u00e2n r\u1ed3i k\u1ebft lu\u1eadn s\u1ed1 n\u00e0o nhi\u1ec1u ch\u1eef s\u1ed1 h\u01a1n th\u00ec l\u1edbn h\u01a1n (V\u00ed d\u1ee5: nh\u1ea7m t\u01b0\u1edfng
7,25 > 7,3<\/code> v\u00ec ngh\u0129 25 l\u1edbn h\u01a1n 3). Quy t\u1eafc \u0111\u00fang l\u00e0 so s\u00e1nh t\u1eebng h\u00e0ng t\u1eeb tr\u00e1i sang ph\u1ea3i: h\u00e0ng ph\u1ea7n m\u01b0\u1eddi c\u1ee7a | |
![\"\u0110\u1ec1](\"https:\/\/navi.edu.vn\/blog\/wp-content\/uploads\/2026\/10\/de-cuong-on-tap-giua-ki-1-toan-5-tom-tat.png\")
![\"T\u00ecm](\"https:\/\/navi.edu.vn\/blog\/wp-content\/uploads\/2026\/10\/de-cuong-on-tap-giua-ki-1-toan-5-2-300x188.png\")