Tính 3 4 x 5 6
Tính nhẩm
5 x 6 = ..... 2 x 6 = ..... 3 x 6 = ..... 4 x 6 = .....
6 x 5 = ..... 6 x 2 = ..... 6 x 3 = ..... 6 x 4 = .....
30 : 6 = ..... 12 : 6 = ..... 18 : 6 = ..... 24 : 6 = .....
30 : 5 = ..... 12 : 2 = ..... 18 : 3 = ..... 24 : 4 = .....
5 x 6 = 30 2 x 6 = 12 3 x 6 = 18 4 x 6 = 24
6 x 5 = 30 6 x 2 = 12 6 x 3 = 18 6 x 4 = 24
Tính nhẩm:
5 x 6 = 30 2 x 6 = 12 3 x 6 = 18 4 x 6 = 24
6 x 5 = 30 6 x 2 = 12 6 x 3 = 18 6 x 4 = 24
30 : 6 = 5 12 : 6 = 2 18 : 6 = 3 24 : 6 = 4
30 : 5 = 6 12 : 2 = 6 18 : 3 = 6 24 : 4 = 6
Học tốt <3
5 x 6 = 30 2 x 6 = 12 3 x 6 = 18 4 x 6 = 24
6 x 6 = 30 6 x 2 = 12 6 x 3 = 18 6 x 4 = 24
30 : 6 = 5 12 : 6 = 2 18 : 6 = 3 24 : 6 = 4
30 : 5 = 6 12 : 2 = 6 18 : 3 = 6 24 : 4 = 6
Tính giá trị biểu thức:
1 x 2 x 3 x 4 x 5 x 6 + 2 x 4 + 3 x 3 + 5 x 6 x 7 x 8 - 3 x 4 x 5 x 6 - 2 x 4 x 5
tính bằng cách thuận tiện nhất:
( 2/3 x 4/5) x 5/6 (4/5 + 5/4) x 3/4 27/12 + 17/6 - 25/36 - 15/6
`(2/3xx4/5)xx5/6`
`=2/3xx4/5xx5/6`
`=2/3xx4/6`
`=2/3xx2/3`
`=1`
__
`(4/5+5/4)xx3/4`
`=(16/20+25/20)xx3/4`
`=41/20xx3/4`
`=123/80`
__
`27/12+17/6-25/36-15/6`
`=(27/12-25/36)+(17/6-15/6)`
`=(81/36-25/36)+2/6`
`=56/36+2/6`
`=56/36+12/36`
`=68/36`
`=17/9`
Tính: a) 3 x 4 x 7 / 5 x 3 x 4 b) 2 x 5 x 6 x 8 / 6 x 2 x 8 x 9 c) 4 x 5 x 6 / 3 x 10 x 8
`(3xx4xx7)/(5xx3xx4)=7/5`
`(2xx5xx6xx8)/(6xx2xx8xx9)=5/9`
`(4xx5xx6)/(3xx10xx8)= (4xx5xx6)/(3xx5xx2xx4xx2)= 6/(3xx2xx2)= 6/(6xx2)=1/2`
\(a,\dfrac{3\times4\times7}{5\times3\times4}=\dfrac{7}{5}\)
\(b,\dfrac{2\times5\times6\times8}{6\times2\times8\times9}=\dfrac{5}{9}\)
\(c,\dfrac{4\times5\times6}{3\times10\times8}=\dfrac{2}{4}=\dfrac{1}{2}\)
Tính nhẩm
3 x 4 = 2 x 6 = 4 x 3 = 5 x 6 =
3 x 7 = 2 x 8 = 4 x 7 = 5 x 4 =
3 x 5 = 2 x 4 = 4 x 9 = 5 x 7 =
3 x 8 = 2 x 9 = 4 x 4 = 5 x 9 =
Học sinh nhẩm và ghi kết quả như sau:
3 x 4 = 12 2 x 6 = 12 4 x 3 = 12 5 x 6 = 30
3 x 7 = 21 2 x 8 = 16 4 x 7 = 28 5 x 4 = 20
3 x 5 = 15 2 x 4 = 8 4 x 9 = 36 5 x 7 = 35
3 x 8 = 24 2 x 9 = 18 4 x 4 = 16 5 x 9 = 45
3 x4 = 12
3 x7 = 21
3 x5 = 15
3 x8 =24
2 x 6= 12
2 x8 = 16
2 x4 =8
2 x9 =18
4 x3 =12
4 x7 =28
4 x9 =36
4 x4 =16
5 x6 =30
5 x4 =20
5 x7 =35
5 x9 =45
3 x 4 = 12 2 x 6 = 12 4 x 3 = 12 5 x 6 = 30
3 x 7 = 21 2 x 8 = 16 4 x 7 = 28 5 x 4 = 20
3 x 5 = 15 2 x 4 = 8 4 x 9 = 36 5 x 7 = 35
3 x 8 = 24 2 x 9 = 18 4 x 4 = 16 5 x 9 = 45
Tính bằng hai cách :
( 5/4 + 2/5 ) : 5/6 =
3/4 x 2/5 - 3/4 x 2/7 =
2/3 : ( 5/6 x9/10 ) =
c1 :(5/4 + 2/5) : 5/6 = 33/20 : 5/6 = 99/50
c2 :(5/4 + 2/5) : 5/6 = 5/4 : 5/6 + 2/5 : 5/6 =99/50
c1 : 3/4 x 2/5 - 3/4 x 2/7 = 3/4 x (2/5 - 2/7) = 3/4 x 4/35 = 3/35
c2 : 3/4 x 2/5 - 3/4 x 2/7 = 3/35
c1 : 2/3 : (5/6 x 9/10) = 2/3 : 3/4 = 8/9
c2 : 2/3 : (5/6 x 9/10) = 5/6 : 2/3 x 9/10 : 2/3 = 27/16 * cái này chx chắc:"> quên mất cách lm;-;"" "
Tính :
a ) 2/5 + 4/5 : 5/6 =
b ) 7/3 - 2/3 x 4/5 =
c ) 6/5 : 10 x 5/2 =
d ) 4 : 8/9 + 3/4 =
a ) 2/5 + 4/5 x 6/5 = 2/5+24/25 = 34/25
b ) 7/3 - 2/3 x 4/5 = 7/3 - 8/15 = 9/5
c ) 6/5 : 10 x 5/2 = 6/5 x 1/10 x 5/2 = 3/10
d ) 4 : 8/9 + 3/4 = 9/2 + 3/4 = 21/4
tính
1/2 + 3/4 - 5/6
( 5/6 + 3/8 ) x 2/7
( 7/6 - 3/4 ) : 3/5
6/7 x 2/3 : 5/7
nhanh lên
`1/2+3/4-5/6=6/12+9/12-10/12=5/12`
`(5/6+3/8)xx2/7=(20/24+9/24)xx2/7=29/24xx2/7=29/84`
`(7/6-3/4):3/5=(14/12-9/12)xx5/3=5/12xx5/3=25/36`
`6/7xx2/3:5/7=6/7xx2/3xx7/5=4/5`
` 1/2 + 3/4 - 5/6 = 6/12 + 9/12 - 10/12 = 5/12`
` ( 5/6 + 3/8) xx 2/7 = ( 20/24 + 9/24) xx 2/7 = 29/24 xx 2/7 = 29/84`
` ( 7/6 - 3/4) : 3/5 = ( 14/12 - 9/12) : 3/5 = 5/12 : 3/5 = 5/12 xx 5/3 = 25/36`
` 6/7 xx 2/3 : 5/7 = 6/7 xx 2/3 xx 7/5 = 4/5`
` 1/2 + 3/4 - 5/6 = 6/12 + 9/12 - 10/12 = 5/12`
` ( 5/6 + 3/8) xx 2/7 = ( 15/24 + 9/24) xx 2/7 = 29/24 xx 2/7 = 29/84`
` ( 7/6 - 3/4) : 3/5 = ( 14/12 - 9/12) : 3/5 = 5/12 : 3/5 = 5/12 xx 5/3 = 25/36`
` 6/7 xx 2/3 : 5/7 = 6/7 xx 2/3 xx 7/5 = 4/5`
Bài 1 : Tính bằng hai cách
a) ( 6/11 + 5/11 ) x 3/7 =
b) 3/5 x 7/9 - 3/5 x 2/9 =
c) ( 6/7 - 4/7 ) : 2/5 =
d) 8/15 : 2/11 + 7/15 : 2/11 =
Bài 2 : Tính
a) 2 x 3 x4/3 x 4 x 5 =
b) 2/3 x 3/4 x 4/5 : 1/5 =
c) 1 x 2 x 3 x 4 / 5 x 6 x 7 x8 =
d) 2/5 x 3/4 x 5/6 : 3/4 =
a,Cách 1: (6/11 + 5/11 ) x 3/7 Cách 2 :(6/11 + 5/11) x 3/7
= 1 x 3/7 =6/11 x 3/7 + 5/11 x 3/7
= 3/7 = 18/77 + 15/77
= 3/7
b, Cách 1:3/5 x 7/9 - 3/5 x 2/9 Cách 2 :3/5 x 7/9 - 3/5 x 2/9
= 7/15 - 2/15 = 3/5 x (7/9 - 2/9 )
= 1/3 = 3/5 x 5/9
= 1/3
c, Cách 1:(6/7 - 4/7) : 2/5 Cách 2: ( 6/7- 4/7 ) : 2/5
= 2/7 : 2/5 = 6/7 : 2/5 - 4/7 : 2/5
= 5/7 = 15/7 - 10/7
= 5/7
d,Cách 1:8/15 : 2/11 + 7/15 : 2/11 Cách 2:8/15 : 2/11 +7/15 : 2/11
= 88/30 + 77/30 =(8/15+7/15) :2/11
= 11/2 = 1 : 2/11
= 11/2
Bài 2 cậu tự làm nhé !
\(2a.160\)
\(b.2\)
\(c.\frac{8064}{5}\)
\(d.\frac{1}{3}\)
A) ( 2/5× 1/2)×3/8 =?
B)7/9 ×3/5 + 4/9 ÷3/5=?
Trong các phép tính sau, những phép tính nào làm đúng? ( CHỌN NHIỀU ĐÁP ÁN )
A 3/4 + 1/3 = 3+1 /4 + 3 = 4/7
B 7/9 - 1/3 = 7- 1/ 9- 3 = 6/6 = 1
C 6/7 x 2/5 = 6x2 / 2x5 = 12/35
D 5/6 : 1/3 = 5/6 x 3/1 = 5/2