\(\frac{1}{2}-\frac{-2}{5}+\frac{1}{3}+\frac{5}{7}-\frac{-1}{6}+\frac{-4}{35}+\frac{1}{4}\)
\(=\left(\frac{1}{2}+\frac{1}{4}\right)+\left(\frac{1}{3}+\frac{1}{6}\right)+\left(\frac{2}{5}+\frac{5}{7}-\frac{4}{35}\right)\)
\(=\frac{3}{4}+\frac{1}{2}+1\)
\(=\frac{3}{4}+\frac{2}{4}+\frac{4}{4}\)
\(=\frac{10}{4}=\frac{5}{2}\)