You can multiply the numerator and the denominator by 4, as shown in part B above. But you cannot multiply the numerator by 4 and the denominator by 2. The numerator and the denominator of a fraction must be multiplied by the same nonzero whole number in order to have equivalent fractions.You may be wondering why this is so.xample 4. Multiplying the numerator and the denominator of a fraction by the same nonzero whole number will change that fraction into an equivalent fraction, but it will not change its value. Equivalent fractions may look different, but they have the same value. Let's look at some more examples of equivalent fractions.