dễ mà
21 + 8+ 9 + 5 + 6 4 =107
đúng 100%
21 + 8 + 9 + 5 + 64 = 107
k mk nha````~~!
21 + 8 + 9 + 5 + 64
= 29 + 9 + 5 + 64
= 38 + 5 + 64
= 45 + 64
= 109
21 + 8 + 9 + 5 + 64
= ( 21 + 64 + 5 ) + 8 + 9
= 90 + 8+ 9
= 98 + 9
= 107
k mik nhe
dễ mà
21 + 8+ 9 + 5 + 6 4 =107
đúng 100%
21 + 8 + 9 + 5 + 64 = 107
k mk nha````~~!
21 + 8 + 9 + 5 + 64
= 29 + 9 + 5 + 64
= 38 + 5 + 64
= 45 + 64
= 109
21 + 8 + 9 + 5 + 64
= ( 21 + 64 + 5 ) + 8 + 9
= 90 + 8+ 9
= 98 + 9
= 107
k mik nhe
Tính nhẩm:
4 x 5 =
7 x8 =
45 : 9 =
64 : 8 =
a, ( 3 + 5 + 7 + 9 + ... + 99 ) x ( 5 : 1 - 5 x 1 )
b, 64 x 8 + 71 x 8 - 35 x 8
Tính nhẩm
a) 2 x 6 = ...... 3 x 7 = ......
12 : 2 = ...... 21 : 3 = ......
12 : 6 = ...... 21 : 7 = ......
4 x 8 = ...... 5 x 9 = ......
32 : 4 = ...... 45 : 5 = ......
32 : 8 = ...... 45 : 9 = ......
b) 600 : 3 = ...... 800 : 4 = ...... 400 : 2 = ......
600 : 2 = ...... 800 : 2 = ...... 500 : 5 = ......
Tính nhẩm
8 x 2 = ....... 8 x 3 = ....... 8 x 4 = ....... 8 x 5 = .......
16 : 8 = ..... 24 : 8 = ..... 32 : 8 = ..... 40 : 8 = .....
8 x 6 = ....... 8 x 7 = ....... 8 x 8 = ....... 8 x 9 = .......
48 : 8 = ..... 56 : 8 = ..... 64 : 8 = ..... 72 : 8 = .....
Tính Nhanh:
X = 6 x 8 + 6 x 2 - 5 x 10
A = (90 : 9 + 64) x (6 x 6 - 4 x 9)
a .(18 – 9 x 2) x (2 + 4 + 6 + 8 + 10)
b.(7 x 8 – 56 ) : (2 + 4 + 6 + 8 + 112)
c. (2 + 125 + 6 + 145 + 112) x (42 – 6 x 7)
d.(12 x 6 – 12 x 4 – 12 x 2) x ( 347 + 125)
e(a x 7 + a x 8 – a x 15) : (1 + 2 + 3 + ........ + 10)
f.58 – 58 x (6 + 54 – 60)
g.32 + 63 x a x ( a x 1 – a : 1) + 32 x 8 + 32
h.(1 + 2 + 3 + 4 + .... + 9) x (21 x 5 – 21 – 4 x21)
i.(9 x 7 + 8 x 9 – 15 x 9) : (1 + 3 + 5 + 7 + ........+ 17 + 19)
k.(2 + 4 + 6 + 8 + ... + 20) x (56 x 3 – 72 : 9 x 21)
tính nhanh:
a) 9 x 2 : 2
b) 45 : 9 x 9
c) 10 + 12 + 14 + 16 + ... + 80
d) 217 x 45 + 50 x 217 + 207 x 5
e) 3 x 9 + 18 x 2 + 2 x 9 + 9
g) 2006 x (43 x 10 -2 x 43 x 5) + 100
h) 64 x 4+8 x 3 + 8 + 8 + 8
i) 44 x5 +18 x 10 + 20 x 5
k) 3 x 4 + 4 x6 + 9 x 2 + 18
l) 2 x 5 + 5 x 7 + 9 x 3
Tính nhẩm:
7 x 6 =
63 : 9=
8 x 7 =
64 : 8=