开心一练
$\frac{5}{6}+\frac{4}{9}=$　　$\frac{7}{10}-\frac{1}{5}=$　　$\frac{3}{5}-\frac{1}{4}=$　　$5-\frac{1}{4}=$
$1-\frac{1}{5}-\frac{4}{5}=$　　$5÷0.001=$　　$2.5×4=$　　$\frac{1}{3}+\frac{1}{4}=$
$\frac{1}{3}-\frac{1}{6}=$　　$\frac{11}{15}+\frac{4}{11}+\frac{4}{15}=$　　$1.25×8=$　　$4-\frac{4}{5}-\frac{1}{5}=$

$\frac{5}{6}+\frac{4}{9}=\frac{15}{18}+\frac{8}{18}=\frac{23}{18}$
$\frac{7}{10}-\frac{1}{5}=\frac{7}{10}-\frac{2}{10}=\frac{1}{2}$
$\frac{3}{5}-\frac{1}{4}=\frac{12}{20}-\frac{5}{20}=\frac{7}{20}$
$5-\frac{1}{4}=4\frac{3}{4}$
$1-\frac{1}{5}-\frac{4}{5}=1-(\frac{1}{5}+\frac{4}{5})=0$
$5÷0.001=5000$
$2.5×4=10$
$\frac{1}{3}+\frac{1}{4}=\frac{4}{12}+\frac{3}{12}=\frac{7}{12}$
$\frac{1}{3}-\frac{1}{6}=\frac{2}{6}-\frac{1}{6}=\frac{1}{6}$
$\frac{11}{15}+\frac{4}{11}+\frac{4}{15}=(\frac{11}{15}+\frac{4}{15})+\frac{4}{11}=1\frac{4}{11}$
$1.25×8=10$
$4-\frac{4}{5}-\frac{1}{5}=4-(\frac{4}{5}+\frac{1}{5})=3$

1 熙熙准备花费40元钱准备一顿清凉解暑大餐。
菜谱 绿豆汤 烙饼 凉拌黄瓜 西红柿炒鸡蛋
花费金额/元 15 10 6 9
占总金额的几分之几

1. $\frac{3}{8}$ $\frac{1}{4}$ $\frac{3}{20}$ $\frac{9}{40}$

2 熙熙用豆面和白面烙饼，白面用了0.5kg，豆面比白面少用了$\frac{1}{4}$kg。
熙熙用了多少千克豆面？豆面和白面一共用了多少千克？

2. $0.5-\frac{1}{4}=\frac{1}{4}(\mathrm{kg})$
$\frac{1}{4}+0.5=\frac{3}{4}(\mathrm{kg})$