Giáo án môn Số học Lớp 6 - Tiết 107: Ôn tập cuối năm

 Ngay soan: Ngay day Day lop 6A
  6B
  6 C
 Tiet 107
On tap cuoi nam
 &?
 1. Muc tieu.
 a. Kien thuc: - Hoc sinh duoc on tap mot so ky hieu tap hop: Î, Ï, Ì, Æ, Ç.
 - On tap dau hieu chia het cho 2; 3; 5; 9. 
 - So nguyen to va hop so. Uoc chung va boi chung cua hai hay nhieu so.
 b. Ky nang:- Ren luyen viec su dung mot so ki hieu tap hop. Van dung cac dau hieu chia het, uoc chung va boi chung vao bai tap.
 c. Thai do: - Hoc sinh co y thuc trong khi lam bai tap. 
 2. Chuan bi cua giao vien va hoc sinh:
 a. Chuan bi cua giao vien: - Bang phu ghi cac cau hoi va bai tap. Phieu hoc tap.
 b. Chuan bi cua hoc sinh: - Dung cu hoc tap - Lam cac cau hoi on tap cuoi nam phan so hoc. Cac bai tap
 3. Tien trinh bai day: 
 a. Kiem tra bai cu: 
 Long vao gio on tap 
 b. Day bai moi : 43 phut
Hoat dong cua Thay tro
Hoc sinh ghi
 I. ON TAP VE TAP HOP. (12 phut)
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Doc cac ki hieu : Î, Ï, Ì, Æ, Ç.
Thuoc, khong thuoc, tap hop con, tap rong, giao.
Cho vi du su dung cac ki hieu tren ?
Vi du: 5 Î N, - 6 Ï N, N Ì Z , - 3 Î Z
 N Ç Z = N 
Lam bai 168 (SGK- 66)
Dien ki hieu thich hop (Î, Ï, Ì, Æ, Ç) vao o vuong.
 Z; 0 N; 3,275 N; 
 N Z = N; N Z
Len bang dien - Duoi lop lam vao vo
Tim giao cua tap hop C cac so chan va tap hop L cac so le.
Hay giai thich 
Giao cua tap hop C va L la mot tap rong vi khong co so nao vua la so chan, vua la so le.
Treo bang phu: Bai tap dung hay sai ?
a, ô- 2ô Î N b, (3 - 7) Î Z
c, Ï Z d, N* Ì Z
e, U(5) Ç B(5) = Æ
f, UCLN(a, b) Î UC(a, b) voi a, b Î N
· Su dung ki hieu: Î, Ï, Ì, Æ, Ç.
Vi du: 5 Î N, - 6 Ï N, N Ì Z , - 3 Î Z
 N Ç Z = N
· Bai tap 168 (SGK - Tr. 66)
Giai
 Z; 0 N; 3,275 N; 
 N Z = N; N Z
· Bai tap 170 (SGK - Tr. 66)
Giai
 C Ç L = Æ
Vi khong co so nao vua la so chan, vua la so le.
· Bai tap chep 
 Giai
a, Dung vi ô- 2ô= 2 Î N
b, Dung vi (3 - 7) = - 4 Î Z
c, Sai vi = - 2 Î Z 
d, Dung
e, Sai vi U(5) Ç B(5) = {5}
f, Dung
 II. ON TAP VE DAU HIEU CHIA HET. (12 phut)
GV
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Hay phat bieu cac dau hieu chia het cho 2; 5; 3; 9 
Lan luot tra loi
Nhung so nhu the nao thi chia het cho ca 2 va 5 ? Cho vi du?
Nhung so co tan cung la 0 thi chia het cho ca 2 va 5. Vi du 20 M 2 M 5
Nhung so nhu the nao thi chia het cho ca 2; 5; 3; 9 ? Cho vi du ?
Nhung so co tan cungla 0 va co tong cac chu so chia het cho 9 thi chia het cho ca 2; 3; 5; 9
Ap dung lam cac bai tap sau:
* Bai tap 1: Dien vao dau * de: 
a. chia het cho 3 ma khong chia het cho 9
b. chia het cho ca 2; 3; 5 va 9
c. chia het cho 15
* Bai tap 2: 
a, Chung to rang tong cua 3 so tu nhien lien tiep la mot so chia het cho 3. 
b, Chung to tong cua mot so co 2 chu so va so gom 2 chu so ay viet theo thu tu nguoc lai la mot so chia het cho 11.
Nghien cuu – Hai em len bang lam bai.
Duoi lop lam bai vao vo.
Goi y: Viet so co hai chu so la = 10a + b. Vay so gom hai chu so do viet nguoc lai la gi? 
= 10b + a
Lap tong hai so roi bien doi.
· Dau hieu chia het cho 2; 5; 3; 9 - 
 Sach giao khoa
· Bai tap 1
 Giai
a. 642; 672
b. 1530
c. 15 Þ 3 , 5 
Vay cac so do la: 375; 675; 975; 270; 570; 870
· Bai tap 2
 Giai
a. Goi 3 so tu nhien lien tiep la: n, n + 1, n + 2. Ta co: 
n + n + 1 + n + 2 = 3n + 3 
 = 3(n + 1)
Ma 3 M 3 Þ 3(n + 1) M 3 
Hay (n + n + 1 +n + 2) M 3
b, Goi so co hai chu so da cho la (a, b la chu so; a, b ¹ 0)
Theo de bai ta co:
 = 10a + b + 10b + a
 = 11a + 11b
 = 11(a + b) M 11
Vay tong () M11
III. ON TAP VE SO NGUYEN TO, HOP SO, UOC CHUNG, BOI CHUNG. (14 phut) 
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The nao la so nguyen to. Hop so ?
Tra loi
Trong dinh nghia so nguyen to va hop so co diem nao giong nhau va diem nao khac nhau ? Tich cua hai so nguyen to la mot so nguyen to hay hop so? 
- Giong nhau: Deu la cac so tu nhien lon hon 1
- Khac nhau: So nguyen to chi co hai uoc la 1 va chinh no - Hop so co nhieu hon 2 uoc so 
- Tich cua hai so nguyen to la hop so. 
Vi du: 2.3 = 6 (2 va 3 la nguyen to, 6 la hop so)
UCLN cua 2 hay hay nhieu so la gi ?
UCLN cua 2 hay hay nhieu so la so lon nhat trong tap hop trong tap hop cac uoc chung cua cac so do
BCNN cua hai hay nhieu so la gi ?
BCNN cua hai hay nhieu so la so nho nhat khac 0 trong tap hop cac boi chung cua cac so do.
Dien cac tu thich hop vao cho trong trong bang so sanh cach tim UCLN va BCNN cua hai hay nhieu so ?
Cach tim
UCLN
BCNN
Phan tich cac so ra thua so nguyen to
Chon ra cac thua so nguyen to
Chung
Chung va rieng
Lap tich cac thua so da chon, moi thua so lay voi so mu.
Nho nhat
Lon nhat
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GV
 Lam bai tap sau:
Tim so tu nhien x biet rang:
a. 70 M x; 84 M x va x > 8
b. x M 12; x M 25 va 0 < x < 500
Hoat dong nhom
Chot lai: Tim UC cua 2 hay nhieu so dua vao UCLN cua chung - Tim BC cua 2 hay nhieu so dua vao BCNN cua chung
· Bai tap chep 
Giai
 a. 70 M x ; 84 M x va x > 8
Þ x UC(70; 84) va x > 8 Þ x = 14
b. x M 12 ; x M 25 va 0 < x < 500
 Þ x Î BC (12; 25; 30) va 0 < x < 500
 Þ x = 300
 IV. LUYEN TAP - CUNG CO (5 phut)
GV
Phat phieu hoc tap cho hoc sinh - Hoc sinh lam tren phieu hoc tap 
PHIEU HOC TAP
 Ho va ten: .....................................................................
Bai lam
Dung
Sai
a, Î N
Sai
b, Î Z
Dung, vi = - 5 Î Z
c, 5 Ì N
Sai, vi 5 khong phai la tap con cua N
d, {- 2; 0; 2} Ì Z
Dung
e, 2610 chia het cho 2; 3; 5; 9 
Dung
f, 342 M 18
Sai, vi 342 M 18
g, UCLN (36; 60; 84) = 6 
Sai, vi UCLN (36; 60; 84) = 12 
h, BCNN (35; 15; 105) = 105
Dung
2 phut:d. Huong dan Hoc sinh hoc bai va lam bai tap
 On tap cac kien thuc ve 5 phep tinh cong, tru, chia, luy thua trong N, Z.
 Phan so, rut gon, so sanh phan so.
 BTVN: 169; 171; 172; 174 (SGK - Tr. 66; 67).
 Tra loi cac cau hoi 2; 3; 4; 5.