Giải Bài tập 2 trang 85 Toán 4 tập 2 Cánh diều

a) $\frac{2}{3}+\frac{4}{3} =\frac{6}{3}=2$

$\frac{9}{8}-\frac{1}{8}=\frac{8}{8}=1$

$\frac{1}{6} +\frac{2}{3}=\frac{1}{6}+\frac{4}{6}=\frac{5}{6}$

$\frac{3}{4}-\frac{7}{16}=\frac{12}{16}-\frac{7}{16}=\frac{5}{16}$

b) $9+\frac{2}{7}=\frac{63}{7}+\frac{2}{7}=\frac{65}{7}$

$\frac{3}{8} + 10=\frac{3}{8}+\frac{80}{8}=\frac{83}{8}$

$7-\frac{2}{11}=\frac{77}{11}-\frac{2}{11}=\frac{75}{11}$

$\frac{25}{4}-5=\frac{25}{4}-\frac{20}{4}=\frac{5}{4}$

c) $\frac{2}{3} \times \frac{1}{4}=\frac{2}{12}=\frac{1}{6}$

$\frac{7}{11} \times \frac{11}{2}=\frac{77}{22}=\frac{7}{2}$

$\frac{3}{7} : \frac{4}{9}=\frac{3}{7}\times \frac{9}{4}=\frac{27}{28}$

$\frac{9}{8} : \frac{3}{4}=\frac{9}{8}\times \frac{4}{3}=\frac{36}{24}=\frac{3}{2}$

d) $8 \times \frac{3}{7}=\frac{24}{7}$

$\frac{3}{10} \times 6=\frac{18}{10}=\frac{9}{5}$

$6 : \frac{5}{24}=6 \times \frac{24}{5}=\frac{144}{5}$

$\frac{18}{7} : 3=\frac{18}{7} \times \frac{1}{3}=\frac{18}{21}=\frac{6}{7}$