Question

直接寫(xiě)出得數(shù)． 3 4 ×12=	4 9 ÷ 2 3 =	2 3 - 1 6 =	1 3 + 1 2 =	3 5 -0.6=
1- 1 6 + 5 6 =	8 9 ÷ 2 7 ×0=	30-29.02=	0.0004÷0.0002=	12×2.5%=

Answer 1

分析：①約分計(jì)算；②把除法改為乘法，約分計(jì)算；③④通分計(jì)算；⑤把分?jǐn)?shù)化為小數(shù)計(jì)算；⑥運(yùn)用加法結(jié)合率計(jì)算；⑦0乘任何數(shù)都得0；⑧注意數(shù)位對(duì)齊；⑨把被除數(shù)和除數(shù)分別擴(kuò)大10000倍，再計(jì)算；⑩把2.5%化為小數(shù)計(jì)算．

解答：解：

3

4

×12=9；       

4

9

÷

2

3

=

2

3

；         

2

3

-

1

6

=

1

2

；         

1

3

+

1

2

=

5

6

；            

3

5

-0.6=0；

1-

1

6

+

5

6

=1

2

3

；         

8

9

÷

2

7

×0=0；      30-29.02=0.98；     0.0004÷0.0002=2；    12×2.5%=0.3．

點(diǎn)評(píng)：此題考查了多方面的知識(shí)：約分、通分、數(shù)字轉(zhuǎn)化、運(yùn)算定律以及小數(shù)的數(shù)位對(duì)齊等．