To get the reciprocal of a fraction, just turn it upside down.
Like this (press play button):
Fractions
A Fraction (such as 3/4) has two numbers:
Numerator
Denominator
We call the top number the Numerator, it is the number of parts you have.
We call the bottom number the Denominator, it is the number of parts the whole is divided into.
Reciprocal
of a Fraction
To get the reciprocal of a fraction, just turn it upside down. In other words swap over the Numerator and Denominator.