Not all roles available for this page.
Sign in to view assessments and invite other educators
Sign in using your existing Kendall Hunt account. If you don’t have one, create an educator account.
The purpose of this Number Talk is for students to demonstrate strategies and understandings they have for multiplying unit fractions. These understandings help students develop fluency and will be helpful later in this lesson when students make sense of a unit fraction multiplied by a non-unit fraction.
Find the value of each expression mentally.
The purpose of this activity is for students to draw a diagram representing the product of a unit fraction and a non-unit fraction. Then students use the diagram to represent the product with an expression and find its value. Students may draw many different diagrams that represent the situation. The context of sports fields was chosen to encourage students to divide the square in thirds, vertically or horizontally. Then students divide the two thirds that represent the sports in half, horizontally or vertically, to represent the part of the sports section that will be used for soccer fields. The Activity Synthesis focuses on the expressions and equations that represent the area for the soccer fields. Students reason abstractly and quantitatively throughout as they relate their diagram and the expression representing it to the park (MP2).
A city designs a park on a rectangular piece of land. of the park will be used for different sports. of the land set aside for sports will be soccer fields.
Draw a diagram of the situation.
The purpose of this activity is for students to relate expressions to a diagram in a situation where they represent the product of a unit fraction and a non-unit fraction. Students work with a diagram that represents a different park. Students write expressions, trade with a partner, and interpret their partner’s expressions and match them to a diagram. As students work together, listen for how they explain why the expressions represent the corresponding areas. While the activity focuses on relating expressions and parts of the diagram, in the syntheses students find the value of products and analyze equations in terms of the park (MP2). As students discuss and justify their decisions while looking through each others’ work, they share mathematical claims and the thinking behind them (MP3).
Elena draws this diagram to represent a different park.
“Today we represented the multiplication of a unit fraction and a non-unit fraction with diagrams and expressions.”
Display the park diagram from the last activity.
Display equations:
“Describe to your partner how each equation represents the diagram of the park.”
“What patterns do you notice in the equations?” (Each part of the park is a certain amount of tenths. If we multiply the numerators, we get the numerator in the product. If we multiply the denominators, we get the denominator in the product.)