Giải bài tập 2 trang 99 vbt Toán 4 tập 2 Cánh diều

a) $\frac{2}{7}+\frac{3}{14}=\frac{4}{14}+\frac{3}{14}=\frac{7}{14}=\frac{1}{2}$

$\frac{2}{3}+\frac{1}{12}=\frac{8}{12}+\frac{1}{12}=\frac{9}{12}=\frac{3}{4}$

$8+\frac{7}{4}=\frac{32}{4}+\frac{7}{4}=\frac{39}{4}$

$\frac{6}{5}+4=\frac{6}{5}+\frac{20}{5}=\frac{26}{5}$

b) $\frac{9}{16}-\frac{1}{4}=\frac{9}{16}-\frac{4}{16}=\frac{5}{16}$

$\frac{7}{3}-\frac{2}{9}=\frac{21}{9}-\frac{2}{9}=\frac{19}{9}$

$6-\frac{3}{10}=\frac{60}{10}-\frac{3}{10}=\frac{57}{10}$

$\frac{18}{5}-2=\frac{18}{5}-\frac{10}{5}=\frac{8}{5}$

c) $\frac{2}{3}\times \frac{4}{9}=\frac{8}{27}$

$\frac{7}{10}\times \frac{5}{2}=\frac{35}{20}=\frac{7}{4}$

$\frac{13}{14}\times 4=\frac{62}{14}=\frac{31}{17}$

$5\times \frac{2}{7}=\frac{10}{7}$

d) $\frac{8}{5}:\frac{2}{5}=\frac{8}{5}\times \frac{5}{2}=\frac{8}{2}=4$

$\frac{6}{21}:\frac{3}{4}=\frac{6}{21}\times \frac{4}{3}=\frac{24}{63}=\frac{8}{21}$

$\frac{6}{13}:3=\frac{6}{13}\times \frac{1}{3}=\frac{2}{13}\times \frac{1}{1}=\frac{2}{13}$

$9:\frac{3}{8}=9\times \frac{8}{3}=3\times \frac{8}{1}=24$