$a)\frac{4}{5}+\frac{1}{10}=\frac{8}{10}+\frac{1}{10}=\frac{9}{10}$

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

$c)\frac{2}{3}+\frac{1}{5}=\frac{10}{15}+\frac{3}{15}=\frac{13}{15}$  

$d)\frac{4}{7}+\frac{1}{2}=\frac{8}{14}+\frac{7}{14}=\frac{15}{14}=1\frac{1}{14}$

$e)\frac{8}{9}-\frac{1}{3}=\frac{8}{9}-\frac{3}{9}=\frac{5}{9}$

$f)\frac{3}{10}-\frac{1}{5}=\frac{3}{10}-\frac{2}{10}=\frac{1}{10}$

$g)\frac{4}{5}-\frac{2}{3}=\frac{12}{15}-\frac{10}{15}=\frac{2}{15}$

$h)\frac{5}{7}-\frac{1}{4}=\frac{20}{28}-\frac{7}{28}=\frac{13}{28}$

$i)2\frac{2}{5}+3\frac{1}{2}=2\frac{4}{10}+3\frac{5}{10}=5\frac{9}{10}$

$j)4\frac{3}{7}+2\frac{2}{3}=4\frac{9}{21}+2\frac{14}{21}=6\frac{23}{21}=7\frac{2}{21}$

$k)2\frac{3}{8}+1\frac{1}{6}=2\frac{9}{24}+1\frac{4}{24}=3\frac{13}{24}$

$l)4\frac{1}{2}+2\frac{3}{5}=4\frac{5}{10}+2\frac{6}{10}=6\frac{11}{10}=7\frac{1}{10}$

$m)4\frac{1}{4}-2\frac{2}{3}=4\frac{3}{12}-2\frac{8}{12}=3\frac{15}{12}-2\frac{8}{12}=1\frac{7}{12}$

$n)5\frac{1}{9}-1\frac{5}{6}=5\frac{2}{18}-1\frac{15}{18}=4\frac{20}{18}-1\frac{15}{18}=3\frac{5}{18}$

$o)3\frac{1}{15}-1\frac{1}{10}=3\frac{2}{30}-1\frac{3}{30}=2\frac{32}{30}-1\frac{3}{30}=1\frac{29}{30}$

$p)5\frac{5}{13}-3\frac{1}{2}=5\frac{10}{26}-3\frac{13}{26}=4\frac{36}{26}-3\frac{13}{26}=1\frac{23}{26}$