TD CHUI; flll THOAI TRONG VIEC LOA CHON KIEN THUi; TOAN HOC VAN DUNG VAO GIAI QUYET CAC BAJ TOAN Ttf THU^C T I I N ThS N G U Y i N P H U O N G T H A O '''' HUYNH THANH LIEM'''' Baivietdupe thiet lap nham gi[.]
TD CHUI; flll THOAI TRONG VIEC LOA CHON KIEN THUi; TOAN HOC VAN DUNG VAO GIAI QUYET CAC BAJ TOAN Ttf THU^C T I I N ThS N G U Y i N P H U O N G T H A O ' - HUYNH T H A N H L I E M ' B aivietdupe thiet lap nham giup hpc sinh (HS) suy nghT, phan tich va dUa quyet djnh lya chpn kie'n thdc toan hpe phii hpp de van dung vao giai q u y ^ cac bai loan thye tien ( B i l l ) ma cae em gap phai cude sd'ng Tu dd, HS hieu dupe nhihig dieu ii thu, bo ich ma loan hpc mang lai; cd ddng lyc hpc tap va hpc lap tdt mdn Toan; duac eung CO, hoan tiiien han nhiJng kie'n Ihtlc da hpc dtn/dng photiidng I C a s d liluan Trong day hpc toan, viec to'ehu'c dd'i thogi thudng diln qua budc: - Budc //Tgo tinh hudng dd'i ^oaivdasiJC, h£^ dan (cac kTthuatcdthe sudung la: dai eau hoi, su'dyng cau hoi CO ket til ucmd, cau hdi lal ngupc van de ); - Budc2:\\S> giai quyet van de mpt each ddc lap, tien hanh b^o dS vd^ eae bgn khac (cae kitiiuat giao vien (GV]cd tiie sir dyng: cho HS mdt thdi gian nhat djnh de suy nghT sau dua eau hoi, cdsy hudng d i n cho HS khican ); - BudcS.Cac nhdm trinh bay ket qua da thao lugn (cac kT thuat thudng sddyng: GV khuyen khich HS trinh bay van de, kel luan nhimg ket qua dung eua HS ); - Budc 4: Td'ng ket va ket lugn Theo chiing toi, mpt linh hudng ddi thoai can thda man mpt frong cac yeu cau sau: • Tinh huwg cd nhieucicbq'iaiquyet,Vdi6, HS selim dupe phuang an tdi uu de md rpng hogc dao sau van de; - Tinh huongdindeh HSdSmicsailam,chOadi/nqnhmg khd khan de HS tham nhap van de; - Tinh hudng chua dt/ngnhsu ngi dung phong phu, GV can cdtiidi gian de day hpc hpp tac mang linh chalgtjrt dpng eo Mpt so bien phap thyc hien viec to chiic doi thoai day hoc toan i) Toehue eho HS do'i thoai devan dung kien thue toan hgc vao giai quye't BTTJ thdng qua viec giai thich cac hien tugng TTbing kien thuc toan hgc, hoae mo hinh hda tinb huong TTbing ngon ngdtoan hge; sau do, ehuyen BTtuTT ve cac BT tong toan hoc Vidti /.-TaiTP Long Xuyen, ngudi la muon xay hai nha may lpc nude tren nhanh sdng Hau dpe theo (ki 1-8/2014) dudng cho Bdng gan cau Hoang Dieu Hai nha may loc nudc duac thiet ke lai hai diem A each bd3m va 5cach bd4m, vdi / I , Snam cung phia vtS so vdi bdsdng Hay tim mdt dja diem C(nlm tren bo^de xay dyng mot tram phat dien dua (Sen vecho hai nha may cho chi phi danh cho ducmg day d i n dien la it nhat Kie'n thuc toan hpc dupc lya chpn vao giai quye'l van de \a:"Cho hai diem A, B nim cung phia doi vdi dudng ffiang (d) Xac dinh vi tn cua diem C tren (d) cho kin AC + BC la be nhaf Tuy theo trinh dp cua HS ma GV cd the lam rd thdng tin de BT trd nen de dang han: Hai nha may dupe xay dyng ben bd mpt song tgi hai dja diem A va B, vdi A{2;3}; B(-1 ;4) Hay tim cgnh bd sdng (dupc xem nhulnjc hoanh) mpldja diem Cvcfi tpa dp C(x;y) n h ^ xay dyng mpt trgm bam dua nude ve cho hai nha may, eho dp d a dudng dng d i n nudc la ngan nhat 2) Dat eiu hdi: "Neu em la " Bat dau tdmot van 6e6\sac dalra thyc te To' chirc van de theo eae khai niem loan hpc va xae djnh kien thuc toan hpc phu hpp Khdng ngtJngxem xet thyc le thdng qua eae qua trinh nhu: dat gia thuyet, td'ng quat va hinh ttiiic hda, ehuyen cae van dethyc te mpt BTdai dien cho b a canh thuc le 'TrB9ig Dai boc An Giang " Cao hfc kboa 19, TnTflngfiaibpc Can Hitf Tap chi Gido due so 339 55 4.GiaiquyetBT Tim mpt ldi giai cho BT co y ngiiTa boi canh llii;c le, sau xac ajnh nhiing han che cua icii giai GV CO the yeu cau HS (Jat minh vao linh huong l-l)l_n(n-HX'n-2) Vay, long sd qua cam xep den tang thd n la: _ n(n + lKn + 2) ^ Suy ra, td'ng sd'qua cam xep de'n lang thu'30 la: dmditang dupc chia, cd hai dgng hinh: la/ucsrac va luc giic deuxen ke Khi dd, ed the chia cac tang tren phan: - Phan /.gdm nhimg tang ed hinh luc giae deu, tuong dng vdi mdi tang la mpt so hang cua day so sau: ( u j : 1,7,19,37, ; - Phan 2: gom cac lang cd hinh lue giae, tuong ung vdi mdi tang la mdt sdhang cua day so: («|,): 3,12,27,48, i „ = « t t ] M ± ^ = 4960 Tn/dng hep 2: Xep theo hinh vudng (xem hinh 1b).Tisang ty, detim cdng thde lo'ng quattinh long sd qua cam xep den lang thdn (tang day), ta cdthe thyc hien theo cac budc sau: Budc /;Chia eae qua cam xep ehdng len tdng lang: tdtang den lang n Tuang ung vcs mdi tang la mdt sdhang cua day so: (i/J: 1,4,9,16, 25,36, SiWc^.'Tim sdhang td'ng quat u^va u^ cua hai day sdfren Xet day (uj, co: y( = \, y( = y( + 6.2, y f = ^ + 6.3 ^ y{=/+6.\, = if^+ 6(n-2), cpng ve theo ve: «_, = l + 6[l + + + ( n - l ) ] = + 6(1+ + + n ) - « = l + « ( « + l ) - n = n ' ^ n + l (1) Xet day « ) : Hinh lb Butfc^; Tim sdhang tongquatu„ cua day so tren Vi day so gom cac sd chinh phuang nen so hang tong qual « „ = n ^ Buik 3: Lan lupt xep cac lang chong len theothu'ty:w,,K2, ,M„, la dupe cdng thdc td'ng quat tinh td'ng n so'hgng dau lien eua day la: (ki 1-8/2014) / = ; ^ + 3.3 + 2, 0=i^*3(n-]) / = 3.i, ; ^ = / + + 3.], / =/ + 3.4 + 3.3, + 3(n-2), u'„ =t^+ 3n + 3{n-l) Cpng ve theo ve: M;,=3n + 6[! + + + ( t t - i ) ] = 3/1+6(1 + + + /!) - n = 3«(/i+l)-3rt = 3n' (2) 5u'd'c5;Lan lupt xep cac tang Pphan1vaphan2 chong dan xen vdi theo thii'ty: Tap chi Gido due so 339 57 Wi,«,',«j,u5 ,«„,u^,ta cd: Uj =K, =hU2 =W| + w|,[/3=W| +w| + Wj = f/;+W2, cac BT auoc chpn li/a phai phii hop vcri thuc le, khong qua phLfc lap, vi)a siic doi vcfi HS va the hien linh kha dung, kich thich cac em giai quyetvan de i ^ U^ = U, +U|' + Wj+u; = ( M | + « j ) + («[ + Uj) (/; = M | + M , ' + U J + M ; + M J ^ ( / J + W , f/^„=(«i+Uj+ +M„)+(u;+«j+ +«^) Tai liSu tham khdo Alfred Renhi (Van Nhir Cuong dich) D6l thoai v l t o i n hpc NXB Khoa hoc vd ki thudt H 1975 Nguyen B^ Kim Phinmg phiip day hpc m6n Toin NXB Dai hoc supham, H 2011 SUMMARY Articles are designed to help students to think, analyze and decision making choices appropriate ma th£/, = ! ematical knowledge to apply to resolve the practical problems they encounter in life From there, students ^2n = ("l + "z + ••• + "n) + ("I "*" "2 "*" — + "n) f^^ learn things interesting, useful drugs bring mathematics: motivated learning and good learning math Khi do, ta CO cong thu'c: ll/latkhac,lheo(1)va(2): »,+ + » = (3.1'-3.l + l) + + ( n ' - n + l) = 3(l'+ + n ' ) - ( l + + /i) + (l + + l) - „;+ +„;=3.i'+ +3„'=3(i'+ +„=).*±w?5±ii Cong IhiJc (3) trdthanh: c , - , "1 n(n + lX2jjJ) [;,„, = (/„ +3/.'+ 3n +1 Suy cong IhiJc long quat xep den tang Ihu" n la: To chirc day hoc tai (Tiep theo trang 60) Pham Quang Ti^n - NguySn Thi Chi "Phuong thiic khai thdc gido d^ic mdi irudng lit chuong trinh gido due bdc tiSu hoc" Tap chi NghiSn ciiu phdi triin bin vang, 1/2009 Corina Fiore Hands-on learning for children, 2003 h t t pp::// / w w w e h o w c o m / p r i n t / f a c t s hands on-learning-childrgn.html Dee Dee Donato Definilion of Hands-on training, eHow.com Donna Thacker, What impact does hands-on learning have on Idds'! eHow, 2003 http://www.ehow c o m / p r i n t / f a c t s i m p a c t - h a n d s onlearning-kids html Mary Ghazarian Important of Hands-on activities in learning, 2008 SUMMARY 4n' + 9n^ + 7n + Vay, tong so qua cam xep den lang thii 30 la: Ngoai ra, cdn cd each xep theo hinh thang, hinh thoi, hinh binh hanh Tuy nhien, cac each xep dd can mpt sdlucmg cam Idn hon so vdi each Iren nen khdng can thiet Trong day hpe loan, 16' ehu'c cac tinh huong doi thoai eho HS, GV thucmg si>dung cae hinh thdc doi thogi nhu: ty dd'i thogi; ddi thoai gii^a G V - HS, HS -HS.De qua trinh to'chdc ddi thoai dgt hieu qua cao, 58 Tap chi Gido due so 339 Teaching in the field is the arrangement of teaching activities in the real world combined with assigning pupils of rights and responsibilities to solve study tasks through positive activities such as personal activities, group discussion, collection of responses, etc in order to satisfy pupils' interest In study and enhance teaching effectiveness Teacblngin thefleld has many good points, e.g.: stimulating pupils' activeness cross-curricular teaching, highly practical, able to combine many positive teaching methods and forms at many locations such as parks, public gardens, museums, etc and will provide pupils with learning environment and conditions to self-discover and gain knowledge together Among subjects in elementary education Natural and Social studies In the I", 2"'' and S^ grade and Sciences in the 4"" and 5^ grade provide teachers with many chances to apply this teaching method (kl - 812014) ... ciy den la tim ci/a nd Khdng ngdng bien dd1 thdng tin thdng qua cac thi/c loan hpc de giai quyet: Trong mdi cich sip xep, qua trinh: dat gia thiet ve cac ye''u td quan trpng cua ne''u thuc hien xep... hanh Tuy nhien, cac each xep dd can mpt sdlucmg cam Idn hon so vdi each Iren nen khdng can thiet Trong day hpe loan, 16'' ehu''c cac tinh huong doi thoai eho HS, GV thucmg si>dung cae hinh thdc doi