Nguyen Dire Thang Tap chi KHOA HQC & CONG NGHE 102(02)'''' 93 97 TO CHirc VA Hl/CKNG D A N CHO HOC SINH KIEN TAO KIEN THlTC TRONG HOC TAP PHEP BIEN HINH L 6 P II THPT Nguyen Due Thang Truang THPT Cdm Thu[.]
Trang 1TO C H i r c VA Hl/CKNG D A N CHO HOC SINH KIEN TAO KIEN THlTC TRONG HOC TAP PHEP BIEN HINH L 6 P II THPT
Nguyen Due Thang
Truang THPT Cdm Thuy I - Ihanh Hou
TOM TAT
Van dung quan diem kien t^o trong day hpc, giSo vien (GV) la ngu^i 16 chirc cic hoat dpng hpc tap, xay dung cdc tinh hu6ng, hudng dan hpc sinh tu minh lim l6i, kham pha, chilm ITnh tri thirc
than va cung h6a minh \ho moi trudng xung quanh, hgp tic v6i ngu^fi kh^c de kien tao kien thuc
GV can luu y den nhUng van de' Quan niem c6 trudc ciia HS, tao lap cac ket noi tir quan ni^m da
CO ciia HS vdi kiln thirc mdi; luon lao biu khong khi soi noi, khuyin khich HS the hien quan dilm
va tranh luan vdi nguoi khac; GV chuin bj trudc nhUng cSu hoi "tSf, nhifng tinh huong su pham;
GV t^o CO hpi cho hp dupe tham gia v^o qua trinh danh gia
Tir kh6a: Kien lao kien thirc td chirc, hudng ddn, phep bien hinh, quan nt?m cd Irudc
DAT VAN DE
Van de quan trong cua viec djnh hudng ddi
mdi phuong phap day hgc la "tich cue hoa
boat dgng hgc tap ciia HS" vdi bon dac trung'
Day hgc thong qua to chirc cac hoat dgng de
HS tu kien tao kien thuc, kT nang, thai do;
tang cudng hoat dgng ca the ket hop vdi hgp
tac vdi su hgp tac ban be trong Idp hgc, hinh
thanh va ren luyen kT nang van dyng kien
thiJc vao thuc tiln da dang, ket hgp danh gia
ciia GV vdi ty danh gia cua HS
Theo quan diem kien tao trong day hgc, GV
la ngudi to chuc cac hoat dgng jioc tap, xay
dung cac tinh hu6ng va hudng dan HS tu tim
toi, kham pha va tu ki^n tao kien thirc GV
cin COI trgng viec tim hieu nhiJng quan niem,
nhiJng hilu bilt ciia HS ve kien thirc can hgc
lap tir do xay dyng cac tinh hufing hoc tap
dong thdi tao dilu kien de HS vugt qua dugc
nhUng trd ngai, kien tao kien thirc mdi, Nhu
vay, viec nghien ciiu td chii'c va hudng dan
cua GV theo hudng giiip HS tu kiln tao kiln
thuc la dieu can thiet trong giai doan hien nay
NOl DUNG
Trong [3, tr 103-117], tac gia J.G Brooks va
M.G Brooks cho ring, khi td chuc cac hoat
dong dl HS kiln tao kiln thuc, GV cin chu
trgng den nhiJng van de sau:
- Khuyin khich HS hoat ddng dgc lap va de
xuit nhii'ng sang kien
' Tel 01685276288 Emaii lhangnd275@gmad a
- HS tu de xuat chien luoc giai quyet van de
va dieu chinh khi can thiet
- Tim hieu vl nhirng quan niem trudc do cua HS trudc khi chia se cho ho nhu'ng kien thirc mdi;
- Khuyen khich HS tham gia cac cugc doi thoai vdi GV, vdi cac ban khac
- Khuyen khich HS dua ra nhirng cau hdi dac biet nhirng cau hoi ket thiic md; khuyen khich HS hoi ngudi khac
- Khuyin khich HS the hien quan mem ciia ban than, co the mau thuan vdi gia thiet ban dau, sau d6 co vii hg tranh luan vdi ngudi khac
- GV quy dinh thdi gian dl HS kip thdi xac lap mdi quan he va cai dat tri thirc ben trong cau hoi;
- GV khuyin khich nhung suy nghT hilu ky
tu nhien ma cac em thudng xu\eii sir dung trong qua trinh hgc
Theo cac lac gia George W Gagnon Jr, and Michelle Collay [4], khi GV thiel kl moi trudng hpc tap kien tao can chii y den nhirng van de sau:
- Tinh hudng: GV to chuc cac tinh hu6ng ma
HS CO the giai thich dugc? GV dua tieu de ciia tinh hu6ng va mieu ta qua trinh giai quyet
cac van dh dua ra; Tra ldi cac cau hoi; Cai dat
cac tri thuc tiem an trong moi tinh huong; Lien kit cac phuang an giai quyet; Thiet lap muc tieu; Tinh hu6ng chua dung nhung gi ma
Trang 2HS mong dgi, cung nhu each giai quyet van
de CO y nghTa
- Nhom: GV tao nhom HS nhu the nao?
+ Co the loan bg ldp hgc ho^c co the la mgl
nhom gom hai I IS trd len
+ GV sip xep nhdm lai liC'u sao cho I IS co the
sir dung dc li giai ciic linh huong biing Ciic mo
hinh do thi, mieu ui so hgc hoac viiit vc tap
hop nhirng von kinh nghipm GV can xac
djnh ro so thanh vicn trong mgt nhom can
thiel lap la bao nhieu
- Lien kel- Tao dyng cac lien ket tii' kien thirc
da CO ciia HS vdi nhirng gi ma hg cd the thu
dugc thung qua li giai cac tinh huong GV co
the dua ra mgl van dc don gian de HS trong
Idp ciing thao luan, giai quyel van de dat ra,,,
trudc khi cho hg tham gia vao hoal dgng nhom
- Cdu hdi: Cau hoi co the xual hien trong loan
bg thiet ke cac boat dong kien tao cho HS
Cau hdi hudng dan dugc dua vao trong moi
linh huong day hoc tao nen sy lien ket dong
thdi giiip duy tri hoat dgng hgc tap xay ra
thu'dng xuyen, cung co the diing de thuc dye,
dgng \ien va khuyen khich HS hgc tap GV
can du dinh trudc nhirng cau hoi, cung nhu
nhirng cau hoi va cau tra Idi ciia HS
- Sir the hien- GV khuyen khich HS trinh bay
quan diem bat cu no la gi trong khi giai quyel
cac linh huong Chimg dugc ghi chep lai tren
bang hoac vao mau giay hoac co the minh hga
qua sa do, bang bieu, ghi am, chup anh hoac
quay video,
- Sir nhdn xel vd ddnh gid:
Trong qua trinh HS li giai nhung tinh hudng
hg CO the dua ra cac nhan xet va sau do quan
sat su the hien ciia cac ban khac Thai do, kT
nang va nhirng hieu bilt ma HS ITnh hpi dugc
la gi? Nhirng gi ma HS ITnh hdi dugc ma
khong bj lang quen Nhirng gi HS da bilt,
nhirng gi ho da muon biet, HS da hgc nhu thi
nao? GV tao dieu kien de HS dugc danh gia
lan nhau trong qua trinh hgc tap
Tir nghien cuu cac quan diem cua cac tac gia
tren chiing toi cho rang, trong day hgc mon
Toan theo hudng to chuc cho HS kiln tao kiln
thirc thi hoat dgng ciia GV co dac dilm sau:
- GV xay dung kjch ban day hgc, xay dyng
cac tinh hu6ng day hgc dua tren kit qua vl
vi^c tim hieu quan nigm da cd ciia HS ve noi dyng hgc tgp GV phan loai va danh gia cac m$t kien thirc, kT nang da c6 cua HS
- GV chuan bj nhu'ng cau h6i "tot" nhim djnh hudng qua trinh kiln tao ciia HS, dy kien cac tinh huong c6 the xay ra va each to chirc cac tinh huong ay Dac bi?t can chii y den nhihig cau hoi nhu Tai sao? The nao? La gi?
- Dicu quan trgng khi HS tiep can vdi tinh huong la GV tao ra dugc sy lien ket giiia kiln Ihirc da cd ciia HS v^ tri thii'c can kien tao Dl lam dugc dieu nay, GV nen sir dyng cac bi?n phap nhu cong nSo, thao lu§n nhdm nhiing van de dan gian nhung gan gui vdi ngi dung
se hgc, ggi dgng co xuat phat tir thyc te xung quanh HS, tir chinh ngi dung mon hgc hoac tir khoa hgc khac Tuy nhien, trong tinh huong ggi dgng co ban dau khong doi hoi qua nhieu tri thuc va each giai quylt vin de thuong ngin gon
- Ngoai viec GV t6 chuc cho tirng HS dgc lap kien tgo nen tri thuc GV nen td chuc cac hoat dgng, cac tinh hudng de HS dugc hgc tap theo nhom vi chinh dieu nay se giiip HS hpc tap dugc tir cac ban thong qua giao luu, tranh luan vdi cac ban khac HS rut ra dugc nhieu dieu bd ich
- GV khuyen khich HS tham gia cac hoal dgng tich cue va thudng xuyen doi thogi voi ngudi khac, GV tdn trgng nhiing sang kien
ma HS dua ra, ddng vien de HS tich cue suy nghT, tim tdi de vugt qua dugc cac chuang ngai, CO vii HS tham gia tranh luan, trinh bay quan diem dSt cau hoi (dac biet la nhii'ng cau hoi nhu: Tai sao? The nao'' La gi) va li giai chiing
- GV nen tao dieu kien cho HS dugc tham gia vao qua trinh danh gia va ty danh gia ket qua hgc tap ciia chinh minh
Sau day, chung toi lay mgt s6 vi dy minh hoa qua trinh day hgc tren:
Vi du minh hoa: Trong day hgc bai "Phep vi ty" - Hinh hgc 11 - Nang cao" Tilt 9 theo phan phdi chuang trinh
Vi ngi dung nay dugc chia lam 2 tiet (tiet
9-10 theo theo phan phoi chuang hrinh) chiing toi chi the hien trong ngi dung tilt 9 ciia bai day
Trang 3Giao vien co the to chii'c cho HS kiln tao kiln
thirc nhu sau:
Trudc khi day hoc noi dung ndy, GV vd HS
chudn bi trtrdc nhung cong vi^c sau:
* GV phan tich chuang trinh, chuin chuang
trinh, chuan kien thirc va kT nang
* GV xay dung cac tinh huong, thiet kl cac
hoat dgng: GV yeu cau HS chuan bi nhirng
van de sau Irudc khi tien hanh bai day:
- Xem lai khai niem phep ddi xung tam trong
SGK Hinh hgc 11
- Cac trudng hgp bang nhau ciia tam giac
dong dang (Trang 69-87 SGK Hinh hgc
7-Tap 2).'
- Xem lai bai tich mgt so vdi mgt vecto' trong
SGK Hinh hgc 10(trang 18-23)
- Chuan bi \a\ dung cac tinh hudng
HI' c i t hai tam bia hinh tam giac giong nhau
nhung kich thudc khac nhau
H2: c i t ba tam bia hinh tron da xac djnh
dugc tam ciia chung (Co hai tam bia hinh tron
CO ciing ban kinh bang 2 cm, mgt tam bia
hinh tron co ban kinh bang 4 cm)
- GV tim hieu quan niem co trudc ciia HS:
GV yeu ciu HS hoan thanh cac bai tap sau
day trong philu hgc tap trudc khi tiln hanh
bai day:
Bdi I: Cho mot dilm O c6 dinh, mot diem M
Hay xac djnh diem M' sao cho vecto'
0 M ' = 3.0M
Bai 2 Hay ve mdt vecto MN, sau ^o_dyng
mgt vecta M'N' la anh ciia vecto MW qua
phepvity V{0,2)
Bai 3: Hay ve hai dudng tron co kich thudc
khac nhau
Tim diem I tren dudng thang 0 0 ' sao cho hai tam giac vuong lOA va lO'A' dong dang vdi nhau? Xac djnh ti sd dong dang ay''
* Du kien cac cau hoi chu chot:
CHl: Em hay trinh bay each xac dinh diem M' d bai tap I? Cac can cir de em lam dugc dieu do'' So sanh do dai ciia OM' va OM?
NIU Ihay so 3 bdi mgt so k ^-0 each xac djnh
-dilm M' nhuthe nao?
CH2: Cac em hay cho biet quan he giii'a ba diem O, M, M'? Dau cua k Men quan nhu the nao den vj tri cQa tam vj O va do dai OM' va OM? Xac djnh phep vi ty cin phai biet nhiJng yen to nao?
CH3: Gia su hai tam giac ABC va A ' B ' C ding dang d vi tri nhu hinh ve, Em hay dat hai lam giac ABC va tam giac A ' B ' C d vi tri khac nhau, roi do ban tim tam vi ty va xac dinh ti so vj ty tuong ung (cac em co the dimg thudc, compa, may tinh)''
CH4: Em hay trinh bay each xac dinh vecto
M'N' d bai tap 2? Em cd nhan xet gi ve do
dai CLia M'N' va MN khong?
* Dua tren su chuin bi nhung cong viec ma
GV da giao cho HS GV danh gia nhung quan niem co trudc ciia HS vl ngi dung phep vi tu tren cac phuang dien:
- Nhung kiln thuc lien quan den phep \i tu nhu: Su thing hang ciia ba diem; hai vecto cimg phuang, cimg hudng; tich mgl so vdi mot vecto; Sy dong dang cua' hai tam giac; Khai niem va tich chit ciia cac phep bien hinh
da hgc
- NhQ-ng kT nang ma HS Ihyc hien trong qua trinh ITnh hoi kien thuc: Ve hinh, tinh loan,
do dac,
Vdi viec chudn bi nhu tren Irong liel day GV
CO Ihi Id chdc day hoc nhu sau:
Trudc khi to chirc cac tinh huong day hoc cac boat dgng, GV xac djnh kien thiic va kT nang
Trang 4cLia HS d mii'c dg nao? HS dS chuan bJ day du
nhirng yeu cau ciia GV dua ra chua? Thai dg
ciia ho CO tich cue hay thd o vdi vi?c chuan bj
chicm ITnh kien thiic mdi? GV phai la ngudi
hieu duoc doi tugng IIS trudc khi to chirc
mgt ho^t dgng tuong irng vdi hg thi qua Irinh
kien tgo kicn thiic ciia HS mdi hicu qua
Chang hgn, doi tirgng la nhi'mg IIS dS hieu
dugc Ciic kicn time ve: tich mgt sd vdi mgl
vecto, hai tam giac dong dgng, kT nSng vc
hinh, dyng mgl vecto bang mgl vecto cho
trudc, hieu dugc cac tinh chat ciia phep bien
hinh da hoc "fu\ nhien, mgt chudng nggi ma
HS phai vugt qua la hai hinh kich thudc khac
nhau ma giong nhau thi co mgt phep bien
hinh bien hinh nay Ihanh hlnh kia hay khong?
Chinh dieu nay se thaeh thirc va thu hiit HS
tich cue tim toi de giai quyel van de
GV: Yeu cau HS trinh bay each xac djnh
diem M' d bai tap 1 trong phieu hgc tap da
chuan bj d nha Sau do, khuyen khi'ch HS
trinh bay each giai ciia minh GV sir dung cau
hoi CHl dIhoiHS
Nhom: Em co nhan xel gi ve each lam ciia
ban? Ban da thuc hien tot nhti'ng van de nao?
Nhirng van de nao ban cdn sai sot? Bgn nao
CO each giai quyet khac?
GV chia Idp thanh hai nhom: Hay trinh bay
each xac dinh diem M' sao cho:
OM'^k.OM trong dd O c6 djnh, M la mgt
diem cho trudc,* * 0
Hai nhom lan lugt lap ke hogch va chien luge
de giai quyet van de dugc dat ra nhu: Can xac
dinh diem nao? Du kien nao da cho? Cai cin
lim va cai da cho cd lien he vdi nhau the
nao? Sau do GV yeu cau cac nhom trinh
bay kel qua ciia nhom minh va danh gia, hoan
Ihien ket qua ciia moi nhdm
GV- Sau khi hai nhom da trinh bay hoan thien
san pham ciia minh va trinh bay xong kit qua
GV dua ra nhan xet ring: Vdi mgt gia trj
k^O, moi diem M luon xac djnh mgt dilm
M' tuong irng thoa man dM' = k.OM Do
do, CO mot phep bien hinh bien diem M thanh
diem M' GV yeu cau HS dinh nghTa trong
SGK dirang24
GV: Sir dyng CH2 va khuyen khich HS dua
ra nhan xet
Nhom: GV chia Idp thanh 4 nhom va yeu ciu moi nhdm ty lay hai vi du ve phep vi ty (chi r5 tam vj ty va ti so vj ty), roi xac djnh anh ciia mgt sd diem qua phep vj ty ay Moi nhom nhan xet va danh gia ket qua cua nhdm khac,
HS dua ra cac y kien va tranh luan GV la Irgng tii, la co van, tao bau khong khi soi nii
vi than thi^n
GV: GV su dung CH3, 4 nhdm dugc chia thanh 2 c&p Moi cap chi djnh mgt vj tri khac nhau ciia tam giac ABC so vdi tam giac
A ' B ' C nhung phai tuan thii nguyen tae: Phep
vj ty can tim bien A thanh A', B thanh B', C Ihanh C
Nhdm: Cac cap nhdm thaeh do nhau va dira
ra each giai quyet ciia minh cimg tranh luan vdi cac nhdm khac, roi dua ra ket luan GV: Tu cac vi du da trinh bay, phep vj tirco bao toan khoang each khdng? Bao toan tinh thang hang va thu tu ciia chiing khong? Neu khong anh ciia mgt hinh phy thugc vao yeu
to nao?
Nhom: HS dua ra nhgn dinh ve van de tren Can cir vao cac nhgn dinh cua HS dua ra GV
cd the dieu chinh, giiip do HS dua ra dugc
nhgn xet "khi k ^±], qua phep vi tu anh va
tao anh khdng bang nhau" va "phep vj tu bao loan tinh thang hang va tinh thir tu ciia ba diem thang hang"
GV: GV to chuc tu kiem tra Igi bai tap 2 dS chuan bj trudc do GV chia Idp thanh 4 nhom
va yeu cau mdi nhdm tu tinh bay ket qua GV sudyng CH4
Nhom: Trinh bay each giai ciia nhom va tra Idi cau hdi CH4 Cac ban HS khac trong lop gdp y de hoan thien cau tra Idi GV dieu chinh
va giiip dd hg de hg di den dugc ket luan
MN = 2.M'N'
GV; Neu thay so 2 bdi mgt sd khac k*0,
lieu bieu thuc ve moi quan he ciia hai vecto
M ' W va MN nhu thi nao? Em hay khai
quat bai toan'' Nhom: Cac nhdm lan lugt dua ra quan diem Tir ket qua ciia cac nhdm, GV dieu chinh va xac nhgn nhirng kien thirc ma cac em HS da phat hien HS phat bilu tinh chit 1 cOa phep
vi ty va ghi lai ngi dung tich chit
Trang 5102(02): 9 3 - 9 7 GV: Giao n h i e m vu cho m 6 i n h o m vdi nhiem
vy d u g c phat bieu d y a vao b i n ndi d u n g trong
tinh c h i t 2 ciia p h e p vj t y :
- N h o m 1: P h e p vj t y c6 bao toan tinh t h i n g
hang va t h u t u ciia ba d i l m t h i n g hang?
- N h o m 2: A n h d u d n g t h i n g , tia, dogn t h i n g
qua mgt phep vj t u ?
- N h o m 3 : A n h ciia t a m g i a c q u a m g t p h e p
vj ty?
- N h o m 4: Anh ciia d u d n g tron qua mgt phep
vj t y la gi?
Sau do cac n h o m lan lugt trinh bay k i t qua
ciia minh t r u d c Idp
GV: Khuyen khich HS trinh bay k i t qua tim
dugc trudc l d p , H S khac tranh luan d l hoan
thien, G V chdt Igi van de
KET LUAN
Qua tiet hgc tren chiing tdi thay, G V la ngudi
to chuc va h u d n g dan HS tim toi, phat hien,
giai quyet van de, kien tao kien thuc HS la
ngudi chii d g n g , tich c u e trong hoal dgng d l kien tao kien thirc trong mgt moi trudng than thien, cdi m d va h a p tac G V khuyin khich,
CO vu, d o n g vien, giiip d d HS vugt qua nhung
c h u d n g ngai, nhii'ng kho khan ma khong lam thay cho HS Ro rang, k i l n thuc ma HS ITnh hpi d u g c chinh do HS k i l n tgo nen
T A I LIEU T H A M K H A O
[1] Bp Giao Due va Dao Tao (2007), Sdch gido khoa- Hinh hpc 11- Ndng cao, Co ban, Nxb Giao
due, Ha NOl
[2], Nguyin Ba Kim (2006), Phuong phdp day hgc mdn Todn, Nxb Dai hpc su pham Ha Noi [3] J G Brooks & M.G Brooks (1999), In Search
of Understanding ihe Case for Constructivisl
Cumculum Development Publishers, Virginia USA [4] George W, Gagnon, Jr and Michelle Collay
(2006), Constructivisl learning design Key questions for teaching to standards Corwin Press,
California USA
S U M M A R Y
O R G A N I Z E F O R H I G H S C H O O L S T U D E N T S B U I L D I N G K N O W L E D G E
IN L E A R N I N G G E O M E T R I C T R A N S F O R M A T I O N I N I I T H G R A D E
Nguyen Due T h a n g '
Cam Thuy I high school - Thanh Hoa
Apply constructivisl view of the teaching and learning of alhematics, teacher organize learning Students inuiative and active learning wilh understand and them skills They cooperate with together students to construct of knowledge Teacher pay attention to problems as: conception of students, set up connection conception with new knowledge, create vibrant atmosphere, encourage students to present their conception and to argue, Teacher prepare good questions and pedagogical situations Teacher create opportunities to students participate assessment
Keyword: Construct of knowledge Organize, guide, geometric transformation, conception
Ngdy nhdn bdi:08/l/2012 ngdy phdn bien:26/2/2013 ngdy duyet dang 26/3/2013
TeL 01685276288 Email thangnd275@gmail com