Two fractions can have DIFFERENT numbers but mean the SAME amount! When your 2/4 fill lined up perfectly with the 1/2 mark, that's because 2/4 = 1/2. They are EQUAL fractions, just written differently! 1/2 = 2/4 = 3/6 = 4/8 ... they all land on the very same line. Chefs use this when they measure 1/2 cup using two 1/4 cups. Musicians use it when two short beats squeeze into one long one. Whenever you swap a fraction for an equal one, you're using EQUIVALENT FRACTIONS!