What are fractions?

In this lesson, we will learn:

• How to understand and write fractions using shape models
• How to understand and write fractions using groups of objects
• How to show fractions on number lines

• Fractions are parts of a whole!
• Fractions represent smaller pieces of a total (whole) thing
• Whole shapes are divided into equal parts
• Whole groups are divided into equal smaller groups (number of items)


• If you have $n$ number of equal parts of a shape, then each part is worth $\frac{1}{n}$ of a whole.
• Ex. 8 equal parts; each part is $\frac{1}{8}$ of a whole


• When writing a fraction with numbers, there are two parts:
• The top (the “numerator”) represents how many parts you have
• The bottom (the “denominator”) represents how many total parts the whole is divided into
• Ex.



• Fractions can also represent groups of objects.
• Ex. what fraction of these jellybeans are green?




• If you were to count:
• all the jellybeans it would be: $\frac{12}{12}$ jellybeans
• the jellybeans that were NOT green: $\frac{12 total -3 green}{12} = \frac{9}{12}$ not green
• the jellybeans that ARE green and NOT green: $\frac{3}{12} + \frac{9}{12} = \frac{12}{12}$ jellybeans
• if you add all the different parts of the whole, you will end up with the whole (when the top is equal to the bottom)