The purpose of this activity is for students to use their understanding of multiplication of a unit fraction by a whole number to solve problems. Students use what they know to find the product when given the factors and to find the factors when given the product. This reinforces the idea that any fraction is a multiple of

Students may interpret quantities greater than 1 as a combination of whole numbers and fractions (for example, cups as 1 whole cup and cup) or express them as mixed numbers (such as ). Both are acceptable. If possible, ask students whether and express the same amount, but it is not necessary to discuss the term “mixed number” at this point. (Students will be introduced to mixed numbers in upcoming lessons.)

• Display the table for Monday and ask students to share responses. Record their responses for all to see.
• “How is the numerator changing in each of the ingredients?” (It is multiplied by 2 in each problem.)
• “Why is the denominator different in all of the ingredients?” (A different unit and a different unit fraction are used to measure each ingredient.)
• Ask students to share the expressions for the ingredients in the table for Tuesday. Record each expression and its value as an equation:
• “Why are two of the ingredients not in fraction form?” (They have whole-number units.)

In this activity, students are presented with descriptions of situations and equivalent multiplication expressions. They match each description to an expression that could represent the situation and see that more than one expression can be used, depending on how they interpret the situation. Likewise, students find that one expression can be used to represent different descriptions (MP2).

Students discuss their matching decisions, analyze how the expressions are related, and consider revising the matches they made, if appropriate. When students discuss and justify their decisions they are creating viable arguments and critiquing one another’s reasoning (MP3).

• See the Lesson Synthesis.