Question

直接寫得數(shù)
3.2+7=10.2                               

8

3

÷6=

4

9

                          40×（

4

5

-

5

8

）=7
12×40%=4.8                              50-25%=49.75                     20×18%=3.6

2

9

×

2

9

÷

2

9

=

2

9

                              5-

1

5

÷5=4

24

25

．

Answer 1

分析：①注意數(shù)位對齊；②把除法改為乘法，約分計(jì)算；③先算括號(hào)內(nèi)的，再算括號(hào)外的；④⑤⑥把百分?jǐn)?shù)化為小數(shù)，再計(jì)算；⑦可調(diào)整一下運(yùn)算順序，使計(jì)算簡便；⑧先算除法，再算減法．

解答：解：
3.2+7=10.2                               

8

3

÷6=

4

9

                          40×（

4

5

-

5

8

）=7
12×40%=4.8                              50-25%=49.75                     20×18%=3.6

2

9

×

2

9

÷

2

9

=

2

9

                              5-

1

5

÷5=4

24

25

．

點(diǎn)評(píng)：此題考查了小數(shù)、分?jǐn)?shù)的運(yùn)算，注意小數(shù)點(diǎn)對齊以及運(yùn)算順序，是解題關(guān)鍵．