2. In \( \frac{4}{9}+\frac{1}{9}=\frac{5}{9} \), which is the sum? \( \begin{array}{llll}\text { a. } \frac{1}{9} & \text { b. } \frac{4}{9} & \text { c. } \frac{5}{9}\end{array} \)

The sum in the equation \( \frac{4}{9} + \frac{1}{9} = \frac{5}{9} \) is represented by the final value on the right side of the equation, which is \( \frac{5}{9} \). So, in this case, the answer is option **c. \( \frac{5}{9} \)**. Understanding fractions is crucial in mathematics as they represent parts of a whole. Using common denominators, as in this example with \( \frac{4}{9} \) and \( \frac{1}{9} \), enables easy addition. The entire concept is foundational for more advanced operations involving rational numbers. To avoid mistakes when adding fractions, always ensure that the denominators are the same. If they are not, you must find a common denominator. A common error is adding the numerators directly without keeping the denominators in mind. This will lead to incorrect sums, so double-check before finalizing your answer!