Challenge students' understanding of multiplying fractions by whole numbers to help them form opinions about rules regarding scaling. Use this lesson on its own or as support for the lesson Multiplication as Scaling.
Students will be able to discuss multiplication as scaling.
Students will be able to express an opinion about scaling with fractions using sentence frames and collaborative conversations.
Display three fraction expressions with two numbers on the board where there is one factor in common between all the expressions (e.g., 1/3 x 5/3, 2/3 x 1/3, 3 x 1/3). Ask students to look at the fractions and tell you which answer will be more than one without solving the problem on paper.
Allow students to think on their own for 30 seconds before turning to their partners to discuss the answer.
Tell students that today they'll discuss how to estimate the product of a multiplication problem when the factors are whole numbers and fractions.