第104页 - 亮点给力提优课时作业本五年级数学江苏版

27

6

25

0.6

7

30

3

5

1

2

3

12

5

9

$\frac{9}{10}$

10

$\frac{10}{10}$

7

20

7

$\frac{3}{8}$

$\frac{10} {15}$

A

C

D

$=\frac {7}{8}-\frac {2}{5}-\frac {3}{8}$

$=\frac {1}{2}-\frac {2}{5}$

$=\frac {1}{10}$

$=(\frac {5}{9}-\frac {4}{9})+(\frac {3}{10}+\frac {7}{10})$

$=\frac {1}{9}+1$

$=1\frac {1}{9}$

$=\frac {2}{7}-\frac {2}{7}+\frac {1}{8}+\frac {1}{8}$

$=\frac {1}{8}+\frac {1}{8}$

$=\frac {1}{4}$

$=(\frac {3}{4}+\frac {1}{4})-(\frac {2}{7}+\frac {5}{7})$

$=1-1$

$=0$