1) 12 3/8 + 8 1/6
2) 7 5/6-3 2/3
3) 5 1/16-1/8
4) 9 9/20-5 17/30
5) (18-10 5/9)-(6 1/8- 3 2/3)

[tex]1) 12 \frac{3}{8} +8 \frac{1}{6} =12 \frac{9}{24} +8 \frac{4}{24} =20 \frac{13}{24} \\ 2)7 \frac{5}{6}-3 \frac{2}{3} =7 \frac{5}{6}-3 \frac{4}{6}=4 \frac{1}{6} \\ 3) 5 \frac{1}{16} -\frac{1}{8}=5\frac{1}{16}-\frac{2}{16}=4\frac{17}{16}-\frac{2}{16}=4\frac{15}{16}\\ 4) 9 \frac{9}{20}-5 \frac{17}{30}=8 \frac{87}{60}-5 \frac{34}{60}=3 \frac{53}{60} \\[/tex]
[tex]5) (18-10 \frac{5}{9})-(6 \frac{1}{8}- 3 \frac{2}{3})=7 \frac{4}{9}-(5\frac{27}{24}-3\frac{16}{24}) =7\frac{4}{9}-2\frac{11}{24}=\\=6 \frac{104}{72} -2 \frac{33}{72} =4 \frac{71}{72} [/tex]