\[\begin{aligned} A &= \frac 23 + \frac{\overset{1}{\cancel 5}}{\underset{2}{\cancel 6}} + \frac{\overset{1}{\cancel 3}}{\underset{2}{\cancel{10}}} =\frac 2 3 + \frac 1 4 =\frac{2\times 4}{3\times 4} + \frac{1\times 3}{4\times 3}& \\ &= \frac{8+3}{12} = \frac{11}{12}.& \end{aligned}\] \[\begin{aligned} B &= -\frac17 + \frac27\times\frac15 =-\frac17 + \frac2{35} =\frac{-1\times 5}{7\times 5} + \frac 2 {35} & \\ &=\frac{-5+2}{35} =-\frac 3 {35}.& \end{aligned}\] \[C = -\frac14 + \frac{\overset{1}{\cancel 3}}{4} \times \frac{5}{\underset{2}{\cancel 6}} = \frac{-1}4+\frac58 =\frac{-2}8 + \frac58 =\frac 38.\] \[D = 1 - \frac{1}{\underset{2}{\cancel{10}}} \times \frac{\overset{9}{\cancel{45}}}{10} =1 - \frac9{20} =\frac{20}{20}-\frac9{20} =\frac{11}{20}.\] \[E = \frac29 + \frac{\overset{1}{\cancel 2}}{81}\times\frac{-1}{\underset{1}{\cancel 2}} =\frac 29 - \frac1{81} =\frac{18}{81}-\frac1{81}=\frac{17}{81}.\]