Question

直接写得数
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注意数位对齐；②把除法改为乘法，约分计算；③先算括号内的，再算括号外的；④⑤⑥把百分数化为小数，再计算；⑦可调整一下运算顺序，使计算简便；⑧先算除法，再算减法．

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

．

点评：此题考查了小数、分数的运算，注意小数点对齐以及运算顺序，是解题关键．