Percent to Fraction \( \begin{aligned} 40 \% & =40 \times \frac{1}{100} \\ & =\frac{40}{1} \times \frac{1}{100} \\ & =\frac{40}{100}=\frac{4}{10} \\ & =\frac{2}{5}\end{aligned} \) Replace \( \% \) by \( \frac{1}{100} \)

The concept of converting percent to fraction has roots in how we understand parts of a whole. The word "percent" comes from the Latin "per centum," meaning "by the hundred." This means that when you see a percentage, you're essentially looking at a fraction of 100. Understanding this historical context makes it clear why converting percentages to fractions is so intuitive. In practical terms, converting percentages to fractions is a useful skill—especially in cooking, finance, and mixing ingredients. For instance, if a recipe calls for 25% olive oil and you are making a large batch, turning that into a fraction means you can easily calculate how much you need using simple ratios. Just keep in mind that maintaining precision in measurements is key to achieving the best results!