4. Change this mixed number to an improper fraction. \[ \begin{aligned} 2 \frac{1}{4} & =\frac{4}{4}+\frac{1}{4}+\frac{-}{4} \\ & =\frac{4}{4}\end{aligned} \]

To convert the mixed number \(2 \frac{1}{4}\) into an improper fraction, you first multiply the whole number (2) by the denominator (4), which gives you 8. Then, you add the numerator (1) resulting in \(8 + 1 = 9\). So, the improper fraction will be \(\frac{9}{4}\). Now, let's have some fun with fractions! Did you know that improper fractions can be quite helpful in cooking? For instance, when a recipe calls for 1 and 3/4 cup of flour, it's often easier to measure it as 7/4 cups instead. This way, you can mix and match your measurements without needing to convert back and forth while in the heat of baking!