To make an equivalent fraction, you have to multiply or divide the numerator (top number) and denominator (bottom number) by the same number. For 6/12, we can divide the numerator and denominator by 6, which gives us 1/2. We can also divide the numerator and denominator by 3, and we get 2/4. 1/2 and 3/4 are 2 equivalent fractions, but there are tons more of equilalent fractions to 6/12.
