REN LUYEN Kl NANG SlEU NHAN MCm HOC SINH LOfP 7 TRONG DAY HOC TOAN VE Tl IE THIJfC O ThS NGUYEN V A N THANH* Tpdn hpc Id ntdn khoo hpc co bdn, cd tfnh huu tupng coo nhung cd nhllu ung dyng hong mpl ll[.]
REN LUYEN Kl NANG SlEU NHAN MCm HOC SINH LOfP TRONG DAY HOC TOAN VE Tl IE THIJfC O T pdn hpc Id ntdn khoo hpc co bdn, cd tfnh huu tupng coo nhung cd nhllu ung dyng hong mpl llnh vpc cuo ddl sdng xd ndl u nhllu nude hfin t h i gtdt hl|n nay, vl|c dpy hpc todn f^S thdng khdng d\] Id hong bj cdc kiln thuc CO bdn vd rin luv^n kr ndng gidl bdl tdp hong SGK, sdch tham wido md cdn rdt chu hpng din vl|c rfin luy|n kTndng sifiu nh^n thue (NT) eho hpc sinh (HS) Chfing hpn, hong chuong hinh todn d THCS cuo Singapore Irong tdl ll|u (1) thi «sifiu nhdn thue' metoeognltton hodc «tu v l lu duy* (thinking about thinking) d l cdp din ndng Ipc klem sodt qud trinh suy ngnT cua cd nhdn, ode bl$t Id t ^ v l v i ^ lyo chpn vd su dyng cdc chll^ lupc gidi h>dn Vlie rfin tuyfin Id ndng slfiu KT cho HS nham glup cdc em hieu dupe bdn chdt cdo qud trinh (QT) hoc todn vd gidl todn, bllt h/ khdm phd h-i thue mdl, hilu sdu kiln thuc, nhd Idu vd cd khd ndng vdn kiln thuc da hpc vdo ihpc liln D l rfin luy|n kr ndng slfiu NT cho HS, chung tdl xdc djnh cdc glal dopn (GD) KT euo HS nhu hong sodd Mdl hong nhung diiu quon trpng rfin khd ndng slfiu NT cho HS h-ong dpy hpc todn chinh Id khd ndng Hip cdn Idl gidl mdl bdl todn cdo ede em Khi HS bllt vdn dyng m^t cdch thfch hpp cdc h-l thuc dd hpc vdo QT gidl h:>dn nghTo Id cdc em dd phdt triln dupe h; sdng tpo Khu vdy, HS cdn cd m^l qud h'lnh, dl h> vdn d l (VD) don gidn d i n phdc h?p d l hinh thdnh kT ndng slfiu KT Ddl vdl HS, d l dpi dupe md^ kr ndng slfiu NT, ede em edn hdl quo mdl sd budc t l ^ cpn VD theo cdc cdp dd khde nhou nhv: ,1 J - Nhdn a l | n vdldm sdng G02 GDI T»a tun Huing HutSngdaaTO ^ ' ^ ^ " ^ - ^ • Muc d$ NT cuo HS dux = h o d c x - Lipklnofcti MnnOOng ^ ''± 49 titiOcina XtyNngglt V Bdt Iodn I : T l m x b i l t ^ = | j •MnhgM Moaca uiHi man i^myii Id nhOng VD cdn qugn tdm; - Dua nhOng dd nghj ho^c gidi phdp djnh hudng cho QT gIdi quyitt VD; - Ddnh gid, phdn tich, cdc gidl phdp od d^ hinh thdnh kr ndng nghlAn cOu VD; - Thu ih^p cdc gidl phdp dd dSlilnh thdnh kr ndng situ IMTcOaHS Dgng todn K1$ thi}c Id phdn ki^n thik rdt quan trgng chucmg trinh mdn Todn Idp Khi dgy ngc todn vi phdn H /^ ihik, HS ihudng ^ [ gidl di/gc cdc bdi todn 6art thudn, cdn nnOng bdl khd hon, c d c a m c d t h j r o i vdoih^bk ^ ^ hodc k = - j : _ y _ x + y_4,8 x=2 , , rjr = - V d l k = l t h i r _ r,; ;v vol l kk== l t1hthi i i y Tu^=0,4=>x = 2,8;7=0,4=>y=2.V§y, ''5 ' ' '"• x = 2,8;y = b) Tuong ty, HS cd thi gidl duoc de ddng Bd//odn5;Timx,yblSj = ^ v d x - y = l , Ddl vol dgng todn ndy, GV cdn hudng dSn HS sii dvng Knh chdt cdo ti If thiic d l gidl , ;t y 2y ^ C d c A T u2- = 5^=>5x=2y=>x=-^.Thay ' ã 2y ,ô , r vdo cdng thuc xy= 10=> "r-y= = > / = - y i , 25 =>y = hodcy =-5 [^ = f^ = -2 Vdy, j hodc L , Ti£ => - £ > Z = £ , £ - y ^ i , , 10 10 10-9 Vdl- = l , = > x ; v d l | = l,4=.y=12,d ^ „ Cdc/i5:Tacdxy=10=> j = ^ ( d o c d x v d y phdl khdc 0) Nhilu HS cdn lung lung vl bllu lhiic2x-y= 1,4 ^ d | = ^ => ^ = ^ = ^ => ^ = =• khdng cd tinh chd't CO bdn ciia Hid Ihuc GV 2y 2y cdnn8urachoHSthdydo