calculator®
If the fraction or mixed number is only part of the calculation then omit clicking equals and continue with the calculation per usual. i.e. 3/4 DEC x 6 =. Fraction format button is used to work with all fractions. Also to change a decimal of the form 0.5 to the fraction 1/2, or change a decimal of the form 1.75 to a mixed number of the form 1 3 ...