You can cross multiply. Which means that you multiply the denominator of the first fraction to the numerator of the 2nd fraction.Whichever has the largest number when you multiply will be the largest fractions.
EX: 1/4 and 1/2 you multiply the 4 to the 1 of the second fraction which will total out to 4. Then the numerator of the first fraction which is 1 time the denominator of the second fraction which is 2. Since the bigger number is over the fraction 1/4 that means 1/4 is larger than 1/2.
