In this activity, students multiply fractions by whole numbers and compare fractions to solve problems (MP2). They make comparisons by reasoning about the denominators of the fractions or about equivalence.

• “How did you find the length of the fabric?”
• “How could you find the length of the fabric, using multiplication?”

• Select 2–3 students to share their equations and reasoning.

The purpose of this activity is to practice adding and subtracting fractions. Students reason about different combinations of fractions to make 2. Students can find many combinations by looking for ways to add fractions that have the same denominator. Although not required by the standards for grade 4, the activity also invites students to use their understanding of equivalence to combine fractions with unlike denominators in preparation for grade 5. In the Activity Synthesis, emphasize the ways students used addition and subtraction and reasoned about equivalent fractions.

• Invite 2–3 previously identified students to share their equations and their reasoning.
• “How did you know when your fraction was equivalent to 2?” (I looked for ways to make 1 first. When the numerator is twice as big as the denominator, the fraction is equivalent to 2.)
• “Why can we use multiplication to represent the combination ?” (There are 6 groups of or . Both expressions are equal to or 2.)

The purpose of this activity is to practice adding and subtracting fractions. Students reason about different combinations of fractions, including fractions greater than 1, and the relationship between addition and subtraction. Students also reason about equivalent decimal fractions to add and subtract fractions with unlike denominators (MP7).

• Invite previously identified students to share how they used the decimal fractions to make 1.
• “How did these students use equivalence to help make a total of 1, using these fractions?” (They thought about ways to make all the fractions have the same denominator. They thought about how the fractions compared to 1 to decide how to add or subtract.)