I have been wondering if there is any known way of converitng a decimal number into its exact fractional (possibly a word) value

i know you can type:

ctrl -> / and get a fraction and then input values, then ctrl enter to get a decimal, i was wondering if there was a way to reverse this so you can type in:

1.5 and get (from an unknown comand/s) 3/2

any help would be greatly apreichieeeeeeeated :D XD