Calculations with fractions
| [[$ \dfrac{a}{b} = \dfrac{ka}{kb} \text{, where } k \neq 0 \quad $]] | expanding (→) and reducing (←) |
| [[$ \dfrac{a}{b} +\dfrac{c}{d} = \dfrac{ad+bc}{bd} $]] | addition (with expanding) |
| [[$ \dfrac{a}{b} -\dfrac{c}{d} = \dfrac{ad-bc}{bd} $]] | subtraction (with expanding) |
| [[$ \dfrac{a}{b} \cdot \dfrac{c}{d} = \dfrac{ac}{bd} $]] | multiplication |
| [[$ \dfrac{a}{b} : \dfrac{c}{d} = \dfrac{ad}{bc} $]] | division |