Learning Resource Type

Learning Activity

Slides & Pies - Multiplicative Comparison Lesson

Subject Area

Mathematics

Grade(s)

4

Overview

Students will take a deeper dive into word problems to gain a firm understanding of multiplicative comparison.  They will compare problems using additive vs. multiplicative comparisons and problems where either the set or the product is unknown.  The activity also includes a matching game for students to match equations, models, and comparison statements. 

    Mathematics (2019) Grade(s): 4

    MA19.4.1

    Interpret and write equations for multiplicative comparisons.

    Unpacked Content

    UP:MA19.4.1

    Vocabulary

    • Multiplicative comparison
    • Multiplier
    • Equation
    • Times as many
    • Times as much
    • Verbal statement
    • Factor
    • Product
    • Quantity
    • Multiple
    • Scale factor

    Knowledge

    Students know:
    • How to write an equation to represent a word situation.
    • Which quantity is being multiplied and which factor is telling how many times.
    • Varied language that describes multiplicative comparisons.

    Skills

    Students are able to:
    • Interpret equations for multiplicative comparisons.
    • Write equations for multiplicative comparisons.

    Understanding

    Students understand that:
    • Multiplicative comparisons relate the size of two quantities and a scale factor.
    • Factors in multiplication problems have different roles from each other in the context of comparison problems.
    • Explanations and drawings show ways multiplicative comparisons are similar to and different from equal groups and arrays.
    Mathematics (2019) Grade(s): 4

    MA19.4.2

    Solve word problems involving multiplicative comparison using drawings and write equations to represent the problem, using a symbol for the unknown number.

    Unpacked Content

    UP:MA19.4.2

    Vocabulary

    • Multiplicative comparison
    • Times as many
    • Product
    • Factor
    • Multiplication
    • Equation
    • Symbol
    • Additive comparison
    • Tape diagram
    • Unknown

    Knowledge

    Students know:
    • how to find products and quotients.
    • Recognize situations represented by multiplicative comparison.
    • Distinguish between multiplicative comparison and additive comparison.

    Skills

    Students are able to:
    • Solve word problems involving multiplicative comparison.
    • Write equations using a symbol for the unknown to represent word problems involving multiplicative comparison.
    • Use drawings to represent the word situation involving multiplicative comparison.

    Understanding

    Students understand that:
    • additive comparison focuses on the difference between two quantities and multiplicative comparison focuses on one quantity being some number times larger than another.

    Phase

    During/Explore/Explain
    Learning Objectives

    Learning Objectives

    Students will be able to interpret and write equations for multiplicative comparisons.

    Students will be able to solve word problems involving multiplicative comparison using drawings and write equations to represent the problem, using a symbol for the unknown number.

    Activity Details

    • Present the slideshow to the students.
    • Read the first water slide problem to the students and give them time to solve it.  Students should share equations and models with the class.
    • Read the next water slide problem and tell students they must look closely to see how this problem is different.  Give students time to work and share their solutions with the class. 
    • After students have had time to solve and share both problems, show the solution slide and ask students, "How are these two problems alike?  How are they different?"  Students should notice the difference in phrasing between problems -- "four meters longer" (additive) vs. "four times as long" (multiplicative). 
    • On the next slide, students must choose whether the phrase is additive or multiplicative.  They should pick a phrase from the list and write an equation with a variable (ex: 6 x ? or 2 + d)
    • The next slide has students compare two different multiplicative comparison problems, one with the set unknown and one with the product unknown.  Follow the same procedure as with the water slide problems, allowing time to solve and share each problem before asking students how they are alike or different.  Show the solution slide so students can see the models for each type.
    • After the slideshow, put students into groups of 2-4 and hand out the matching game.  Students must match four cards for each set: word problem, equation, comparison statement, and model.
    Assessment Strategies

    Assessment Strategies

    Use formative assessment strategies during the slideshow and game to determine if students can:

    • interpret and write equations for multiplicative comparisons
    • solve word problems involving multiplicative comparison using drawings and writing equations to represent the problem, using a symbol for the unknown number

    Variation Tips

    The matching game could be played as a whole class interactive activity.  Each student gets one card and has to find their three matching partners.

    Related Learning Activities

    Background and Preparation

    Background / Preparation

    • Preview the slideshow and prepare a way to display it for the class
    • Make copies of the matching game, one for each set of 2-4 students.  You may want to laminate for durability.  Each set is color-coded, so color copies are preferred but not necessary.
    • Teachers will need to create a free account for Teachers Pay Teachers to access the matching game. It is a free download. 

     

    Digital Tools / Resources

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