IfflR RRHG PHinrRG PRlIP ORV HRC H P TRC THCR RHRRI TRONG DAY HOC DINH l l HiNH HOG GHO OOC GINH TRDNG HOG GO S i ThS NGUYEN THANH TRUNG* Trong dgy hpc hpp tae ttieo nhdm (DHHTTN), gido vien (GV) td c[.]
Trang 1IfflR RRHG PHinrRG PRlIP ORV HRC H P TRC THCR RHRRI TRONG DAY HOC DINH ll HiNH HOG GHO OOC GINH TRDNG HOG GO S i
ThS N G U Y E N T H A N H T R U N G *
Trong dgy hpc hpp tae ttieo nhdm (DHHTTN),
gido vien (GV) td chde cho hpe sinh (HS)
hinh thanli cac nhdm hpe tap Cde thanh
vidn trong mdt nhdm cung hpe tap va ed sy trao ddi,
giup dd Idn nhau de hodn thdnh nhiem vy ehung
DHHTTN tgo mdi trudng thudn Ipl, tgo co hdi eho
HS dupe tim hieu, kham phd kiln ttiuc mdi; ddng ttidi,
giup HS phat trie'n cdc nang lye xd hdi nhu: kT nang
sd dung ngdn ngQ, kT ndng giao tilp, kT nang thao
ludn, kT ndng bao ve y kiln eua minh tmdc tap the,
kT nang glal quye't mdu thudn, biet each giai quyet
vd'n d l trong eac tinh hud'ng khde nhau Khi dgy hpc
(DH) eac djnh li (OL) hinh hpc cho HS d tmng hpe
CO sd (THCS), GV can giup HS hie'u dupc rdng, suy
ludn vd chQng minh Id mdt ddc tmng co ban ciia toan
hpc, mpt y l u td quan trpng trong qua trinh DH cac
OL todn hpc Qua dd, HS ndm dupe he thd'ng eac
OL CO ban va mdi quan he glQa chung, cd kT ndng
v|in dung OL vao giai quylt cae van d l toan hpc Vi
v§y, vige van dyng phuang phdp DHHTTN trong
DHOL hinh hpe d T H C S nhdm datduts; nhung myc
ttdu nay
1 Cac con durdng DHOL hinh hoc
DHOL la mdt tinh hud'ng diln hinh trong DH mdn
roa/7 dtmdng phd thdng Theo Nguyin Ba Kim (1),
qua trinh DHOL toan hpc (trong dd cd cac OL hinh
hgc) dupc ttiyc hien bdi mdt trong hai con dudng sau:
1) Con dudng suy diin: Theo con dutimg ndy,
d l DH mdt OL, chung ta thuc hign cac bude: - Gpi
ddng eo hpc tap OL xud't phat td mdt nhu c l u nay
sinh trong thyc tiln hode trong ndi bd toan hpc; - Xuait
phat tai nhOng tri ttiQc toan hpc da bilt, dung suy diln
toge ddn tdi OL; - Phat bid'u OL; Van dyng OL;
- C u n g e d O L
2) Con dudng cd khiu suy doin: Theo eon
dudng nay, de DH mdt OL, ehung ta ttiucaig phai ttiyc
hi§n cae budc sau: - Gpi dpng co hpe tap nhu d con
dudng ttiQnhat; - Dudoan va phat bieu OL; - Chung
minh OL; - Van dyng OL viira tim dupc de giai quyet
v i n d l ddt r a ; - C u n g e d O L
Nhu vdy, diem khae bigt cdn ban glQa hai eon
dudng nay la: theo con dudng cd khdu suy doan, vide dy doan, phat hidn d i l n ra tmdc qua trinh chdng minh OL; edn d eon dudng suy diln thi hai qua trinh nay nhdp lai thanh mdt budc Tuy vao tung ndi dung ey the eua OL de ta cd the chpn mdt trong hai con dudng
2 DH cac OL hinh hoc d T H C S theo phuong phap DHHTTN
Trong DHOL, sQ dyng con dudng cd khdu suy doan se thudn lpl vd gdy hiimg thu hpe tap cho HS Con dudng suy diln cd the dp dyng cho nhQng OL don gian, ddi hdi GV phai sQdyng syphan bdc hoat ddng de^lam bdt khd khdn eho HS GV khdng the hudng dan lan lupt tdng budc md phai dua ra nhiem
vu td'ng quat cho nhdm Ode biet, kiln thde hinh hpc dupc trinhbay theo con dudng k^ hc^ giua ttyc quan
va suy didn B i n g do dac, thyc hdnh, gap hinh, ,
HS cd t h i dy doan cdc dQ kign hinh hgc, taing budc kham pha ra OL Nhidm vy d l ra phai cd tac dyng gpi ddng co chiimg minh va cd the nglm gpi y each chiimg minh OL cho HS Hoat ddng cung cdOL bao gdm: nhdn dang vd thihign OL, chiing minh OL, ap dyng OL vao giai todn thdng qua eac hogt ddng ngdn ngQ, cac thao tac tu duy eo ban nhu khdi quat hda, ddc bigt hda Oe HS ed co hdi dupc hpc tap hpp tac trong gid hpe, GV cd the giao nhidm vu eho taing HS, hudng d i n cac em tim cdc each phdt bilu khde nhau cua OL va tra Idi cdc cdu hdi nhu: mgnh d l dua ra
cd dung ddn khdng? cd nhQng each ndo chiing minh
dupc OL? de chung minh OL ein huy ddng Men ttiuc
nao? GV can gidi thidu eho HS cac bittiQc phuong phap, khde phyc sal lam ciia cae em trong qua trinh lap ludn, chiimg minh OL
Dudi ddy, ehung tdl dua ra mdt vi du minh hpa
v l vide sd dung phuong phap DHHTTN ttong DHOL ttieo con dudng ed khdu suy doan:
Vidu: DHOL "Tdhg ba gde cua mgt tam giic
6i/7ff 18b'"'(Toan 7, tap 1, tr 106)
GV chudn bj phie'u hpe tap (PHT) nhusau:
* Tnrdng THCS Dong Hoa, Bdng Son - Thaih Hoa
Trang 2v e hai tam giac bat ki, diing thude do g6c do 3 g6c cua
m6i tam giac va tinh tong sd do 3 g6c cua mdi tam giac
ay? Em c6 nhan x i t gi v4 tdng ba g6c cua mot tam giac?
Budc 3: Chiing minh OL
PHT aS 2 (nh6m cdt gh6p hinh)
- Cdt mOt tdm bia hinh tam giac ABC
- Cdt rdi gdc B sau dd dat nd k& vdi gdc A
- cat rdl gdc C, sau dd dat k4 vdi gdc
A nhu lilnh 1
HSy ndu di/ doan vd tdng ba gdc A, B, C
cua tam giac ABC HMI
\ A 1
PHT so 3
-Ve A ^ 5 C
- Qua A ke dudng thing xy song song vdfi BC
- Chl ra cAc g6c b i n g nhau trSn hinh? Vi sao?
- T6ng ba g6c cua tam gide ABC bSng t6ng ba g6c ndo
tr6n hinh vd b^ng bao nhi6u?
GV tien hanh DHDL theo cac birdc sau:
Buac 1: Tao dong ca G V dat van de bang each
dua ra bai toan sau:
Bai toan: Cho hai tam giac ABC va tam giac MNI
nhi/ hinh 2:
GV:Lieu ^+fi+c cua AABC co bang M+N+fcm
AMNI khong? HS quan sat vabii6c dau c6 nhung suy
nghT, dir doan va trao da vol cac ban khae de giai quy^
van de
Budc 2: DLT doan va phat bieu DL
Hoal d»ng cua GV
• GV cd th»' 16' chile cho HS
hpc 14P HTTN nhu sau: Idp chia
ihAnh 6 hoSc 7 nh6m, mS'i
nhdm 8 HS Trlnh d^ ciia HS d
ctfc nhdm la tifong dirong
• GV ph^t c4c PHT sd' t 2
eho nhdm lnrdr>g, nhdm trudng
nhdm minh D6ng thdi GV giao
nhi^m vu cho tilng thdnh vidn
ctJa c^c nhdm
- Trong qua irinh HS Ihirc
hinh GV quan sal va gidp dd
thio gd nhdng vtrdng mic cho
HS, nhfl'1 M HS cd hQc lire yft'u
v i kdm
- Khi cic thinh vfAn Irong
nhdm thio lu^n GV c i n cd sir
hirdng dJrt yftu eiu m j i Ihinh
viAn Mn Iri ling nghe i kid'n
cila ban, khdng ngli Ut aau khi
b«n Irinh biy Kong thi minh mdi
nh^n x i i
- Cic nhdm bio cio kS\ qui,
GV nhin xii v i khan ngfri nhJng
nhdm Ihge ht^n nhanh v i cd kA
qui Ihuc hinh chfnh xic
- GV chdt U I vfn 64 Sing
Ihuc hinh do c i t d i n chdng la
du doin duoc Td'ng ba g<fc CUM
mdt lam giic bing T W
Hoat ddng cila HS
- HS thinh l^p nhdm theo ydu c l u cua
GV, m£i nhdm biu nhdm trudng thu ki
- Nhdm trudng nhfin PHT phil cho cic thinh vidn v i kd't hgp vdi GV giao nhi^m vy cho tiing thinh vidn trong nhdm Ching han: thinh vidn IhU nhi't
1 (nhdm do <i^c) Thinh vidn thd 4 Ihd 5
v i Ihd 6 lim thao ydu c l u PHT s5 2
(nhdm cit ghdp hlnh 1)
- Cie thinh vidn nhin nhi^m vg va
thi/c hlnh Iheo ehi din cJa GV va PHT
- HS lim vi^c khln truong trdn lmh thin hgp tic; eie khiu vd hlnh do d^c
e l l dan hlnh phli ehinh xde HS ein dir
f i : !*«+(• = \l+.\*l = 180': • Ktfl qui dg doin PHT sd' 2 l i : &ASC c6
.^•/^+t• = 180"
- Sau khi thue hinh va du doan kSt
qua HS trong m£i nhdm trao doi phid'u
dd kid'm Ira lai mile d$ chinh xac cua qui trlnh thue hlnh v i du doin
- Sau khi kid'm tra, III ca cic thinh Vidn trong nhdm thio lu|n Ihdng nhd't kd'1 q u i Thu k( IJfng hgp lat kd'1 q u i
- O9I di^n eJa nhdm bio cdo kdt qua cua nhdm minh Cic HS khic ling nghe
v i dua ra cic j? kidn trao dtfi bd' sung, chdi vd'n dd'lim rd vd'n dd
• GV giao nhi^m vu cho HS: C/iiJng
minti ring t6ng tja gdc cua m^t lam giic bing IBCf Qi chUng minh OL
nay, GV phat PHT s6 3 cho cac nh6m tn/dmg
- GV theo doi va c6 thd goi y cho HS
nhu sau: xy//AB thi,^^ c6 bang B khong, vi sao? Tutmg tu, A C6
*A,*A, =•>
bing r hay khdng?
vay, suy ra <m~, «.? = •>
- Sau khi mdi nhbm mao luan xong,
GV cho cac nh6m kidm tra chao d l tao khong khi thi dua s6l ndi HS nSm duoc each danh gia kdt qua hQc t$p cija cac nh6m
- GV ygu cau cac nham ci> d^l dl$n trlnh bay each chUng minh
ChOng minh: Qua A kS dudng th^ng
xy//BC, ta cd: ^-^ (hai gdc so Is
trang) (1) ,"•, ^ (hai gdc so le trong)
(2)-TCr (1) va (2) suy ra:
/Sf'+A,+ A =/<H^+«*(*• =
180"-• GV hudng din HS kham pha Ihfim cac each chdng minh khae bSng each tao dodng phy nhu: Qua B kS xy//AC: qua 0 ke xy//AB hoac qua A
ka Ax la lia ddi eua tia AB, ka tia
Ay//BC (xem hinh 4):
Hliili 4
- GV chdt lal vSn ai, nhae lal n$i
dunq PL
- Nhdm tn/dng nhan
PHT va phat cho cac
thanh vi6n eua nhdm minh
HS nhan phiSu, ti/ nghldn cUu, v6 hinh va lan lUTt tra ldi cau hdi Iheo PHT s8 3
- Mil HS tl/ nghldn cdu, sau dd thao luan vdi eac thanh vidn trong nhdm
- HS ed hpe li/c gidl va kha cdn cd su glOp dS,
hd trp eae ban c6 hpc IMC
ydu hon, bdi thdnh tich cua nhdm gdn Udn vdi kdt qud cOa tUng cd nhdn ' Sau khi cdc nhdm thao ludn, thdng nhdt cau trd ldi, d^l didn cOa mSl nhdm trlnh bay each chOmg minh BL vao bdng, sau dd cac nhdm kidm tra chdo Idn nhau
- c a kitp nhdn xdt, danh gia kdt qua
- HS ed Ihd tim dut/c cac each kd dudng phv khae d l chUng minh
B L
Budc 4:Phitb'ieu DL GV yeu clu HS phdt bieu
OL v l tong ba goe eua mpt tam giac
Budc 5: Cung coDL GV giao bai tap eho HS:
Ap dung OL tren, hay tim so do cila goe eon lai trong cae tam giac or/)/>»/) 5;
GV ydu clu eac nhom thuc hien nhanh trong khoang thoi gian la 5 phiit va 5 phiit d l m i l nhom bao cao Idt qua GV chot lai van d l , danh gid nhirng
uu, khuyet diem va chdm diem cho cac nhom hoan thanh nhiem vu tot
Trong qua trinh DH, nlu GV c6 su van dgng linh hoat phucmg phap DHHTTN vao DH cac OL hinh hgc 0 1 ^ 7 thi khong nhiing huting HS vao v i ^ giai
(Xem d^ trang 48)
•(ki2-1/2013)
Trang 3vung NNTH Do dd, dindng eao kha ndng sudung
NNTH cua HS, GV d n ed nhung bign phap huu hieu
de hinh ttianh, ren luydn, phat triln NNTH eho eac
em Dudi ddy, ehung tdi de xuett mdt sd bidn phdp ndng
eao kha nang sudung NNTH cho HS:
1) NN su dung trong giing day ciia GV phai
chuan mue GV can sudung ehinh xdc cac ki liidu,
thudt ngQ toan hqc, thudng xuyen trau ddi kiln thde,
trao ddi vdi ddng nghigp nhi?ng khd khdn v l NNTH
trong giang day
2)GV can trang bi cho HS mdt nen ting tri thuc
NNTH vung chic, giup cae em hie'u sdu sac v l ki
hieu, thudt ngQ toan hpe Cy the, khi hinh thanh
NNTH, GV nen gidi thieu tQ vyng toan hpe trong mdt
ngQ canh ttiich hpp, gkii thieu can ke nghTa, each vilt
vd each sudyng NNTH eho HS HS se khd linh hdi
tu vyng todn hpe nlu khdng gan vdi thuc tiln, do dd,
GV can tgo ra eae ngQcanh hode sQdyng eac hinh
anh tn/e quan d l HS dd ddng linh hpi kiln ttiQc
3) GVein tao eho HS ea hdi ren luyen, phittrien
NNTH Mng qua cac sai lam trong hpc tap GV tgo
ra cae tinh hud'ng sai lim de HS ty phat hien, sau
dd sira ldi hode eho HS phdt hidn ra ldi sai eila ban
vd sua lai cho dung Hpe tap thdng qua sai lim se
giup HS hilu, ghi nhd kiln thde mdt each sdu sde
4)GV ein tieh hep viec ren luyen NNTH vdi viee
hinh thinh, phit trien tri thde eho HS Ren luyen
NNTH eho HS khdng the ehi diln ra trong mdt vai
gki hpe hay mot sd bdl hpc ma can 6uqc thyc hign
thudng xuydn, lien tuc
5)GV tao ea hdi cho HS duge tap luyen sudung
NNTH trong tali ca cic mach kien thik GV can quan
tdm dd'n tat ea cac dd'i tupng HS, tao dilu kign eho
HS dupc phat triln NN ndi ehung va NNTH ndi rieng
6)GV can tao ra mdi tn/dng giao tie'p mi a dd,
HS dugc ren luyen, phit trien kinang giao tiep bing
NNTH G V ed ttii ed sy phdn hda theo trinh dp nhdn
ttiQc, kha ndng phat trien NN cila HS de dgt higu qua
cao trong gid hpc toan
* * *
Phdn tich kit qua khao sat, chung tdl nhdn thay,
kha nang sudyng NNTH cila HS cac Idp dlu cap
tieu hpc trong tipc tap mdn Toin ehua that tdt HS
edn nhilu lung taing, mac sai lim khi ehuyen djch tu
NNTN sang NNTH va ngupe lai, kha ndng si;dyng
NNTH cua cac em cdn nhilu hgn chl Vi vdy, trong
day hpe, GV cin giup HS ndm vQng kiln thuc toan
hpc, ddng thtii, ren luyen kha ndng su' dyng NNTH
ctio eae em; hi dd, gdp phln nang cao chd't lupng
dgy hpe mdn Toin a tieu hpe Q
48 Tap ehi Gido due so 302
(1) Ha Si HO IvihOng vS'n de co bdn cua phuong phdp
day va hpc toan cSp 1 NXB Gido dttc H 1990
Tai li$u tham khao
1 VQ Cao Dam Phuong phap lu$n nghi£n cihi khoa
hpc NXB Khoa hpc vd ki thudt, H 1999
2 Pham Van Hodn - NguySn Gia CO'c - Trdn Thiic
Trinh Giao due hpc mOn Toan NXB Gido diic,
H 1981
3 Eula Ewing Monroe - Michelle P Orme Developing
mathematical vocabulary Preventing School Failure,
Research Library pg 139, 2002
4 DO Dinh Hoan Toan 1 NXB Gido dtic, H 2007
SUMMARY
Mathematical language plays an important role and has a direct impact on students' learning outcomes Therefore In order to improve the quality of students' learning, researchers and educators must proceed from reality This paper presents the survey results
on the ability of using mathematical language of flrstgradesstudentsin primary schoolsin learning Mathematics with the desire to contributively form a factual basis for seeking andproposingmethods
Van dung phuong phap day hoc
(Tief) theo tmng 52)
quylt vin d l todn hpc mdt each tich eye md cdn hinh thdnh cho cac em cac phd'm chat tri tud; tQ dd, gdp
phan ndng cao hieu qua DH mdn Toin6THCS dl
(I) NguySn Bd Kim Phuong phdp day hpc mOn Todn
NXB Dai hpc suphpm, H 2004
Tai li£u tham khao
1 Biii Van Nghi Vdn dung Ii ludn vdo thi^ tiSn d^y
hpc mOn Todn o truthig phd thdng NXB Dpi hpc su
pham, H 2008
2 Dao Tam - Trdn Trung T6 chirc hoat dOng nhdn thiic trong day hpc mtfn Todn ii trudng trung hpc phd thdng NXB Dai hpc suphpm, H 2010
3 NguySn Trung Thanh Td chic dpy hpc hpp tdc
nhdm trong day hpc Hinh Hpc 7 d trudng trung hpc
ca sd Ludn van Thac si Giao due hpc, Truong Dji
hoc Vinh, 2012
4 Phan Dth: Cht'nh (tdng chu bien) Todn 7, tdp I
NXBGidoduc,H.2007
SUMMARY
This paper presents the application of the group cooperation model in g^metric theorem teachingsitu-ations for students to promote positive student learn-ing and meet the requirements of teachlearn-ing geometry
in the Middleschool
— (ki2-1/2013)