$0,9+0,7=1,6$  

$1,6+\frac{2}{5}=1,6+\frac{4}{10}=1,6+0,4=2$  

$2+2\frac{2}{3}=4\frac{2}{3}$  

$4\frac{2}{3}+0,5=4\frac{2}{3}+\frac{5}{10}=4\frac{2}{3}+\frac{1}{2}=4\frac{4}{6}+\frac{3}{6}=4\frac{7}{6}=4+1\frac{1}{6}=5\frac{1}{6}$   

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

$5\frac{1}{2}+\frac{1}{8}=5\frac{4}{8}+\frac{1}{8}=5\frac{5}{8}$  

$5\frac{5}{8}+0,075=5\frac{5\cdot 125}{1000}+0,075=5\frac{625}{1000}+0,075=5,625+0,075=5,7$  

$5,7+\frac{3}{10}=5\frac{7}{10}+\frac{3}{10}=6$  

Sprawdzenia (zielone strzałki):

$0,9+4\frac{3}{5}=\frac{9}{10}+4\frac{6}{10}=4\frac{15}{10}=4\frac{3}{4}=4+1\frac{1}{2}=5\frac{1}{2}$  

$5\frac{1}{6}+\frac{6}{4}=5\frac{1}{6}+\frac{3}{2}=5\frac{1}{6}+\frac{9}{6}=5\frac{10}{6}=5+1\frac{4}{6}=6\frac{4}{6}=6\frac{2}{3}$  , czyli to działanie jest błędnie zapisane

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

$5\frac{7}{10}-5\frac{1}{6}=\frac{7}{10}-\frac{1}{6}=\frac{21-5}{30}=\frac{16}{30}=\frac{8}{15}$