5.NF.A.1 math practice. Learn by doing.

LCD is 6: $\dfrac{3}{6} + \dfrac{4}{6} = \dfrac{7}{6}$.

LCD is 10: $\dfrac{5}{10} - \dfrac{2}{10} = \dfrac{3}{10}$.

LCD is 4: $\dfrac{2}{4} + \dfrac{3}{4} = \dfrac{5}{4}$.

LCD is 24: $\dfrac{18}{24} - \dfrac{8}{24} = \dfrac{5}{12}$.

$\dfrac{2}{6} + \dfrac{1}{6} = \dfrac{1}{2}$.

Same denominator: $\dfrac{6 - 2}{7}$. Result: $\dfrac{4}{7}$.

$\dfrac{6}{8} + \dfrac{4}{8} = \dfrac{5}{4}$.

Same denominator: $\dfrac{5 - 3}{8}$. Result: $\dfrac{1}{4}$.