ALEX Learning Activity

  

Witches Brew With Fractions

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  This learning activity provided by:  
Author: Samantha Wallace
System:Limestone County
School:Cedar Hill Elementary School
  General Activity Information  
Activity ID: 2249
Title:
Witches Brew With Fractions
Digital Tool/Resource:
 
Web Address – URL:
Not Applicable
Overview:

Students will be creating a Halloween-themed recipe and then altering it to feed various amounts of "witches". The students will practice both multiplying and dividing fractions.

This activity results from the ALEX Resource Development Summit.
  Associated Standards and Objectives  
Content Standard(s):
Mathematics
MA2019 (2019)
Grade: 5
12. Apply and extend previous understandings of multiplication to find the product of a fraction times a whole number or a fraction times a fraction.

a. Use a visual fraction model (area model, set model, or linear model) to show (a/b) x q and create a story context for this equation to interpret the product as a parts of a partition of q into b equal parts.

b. Use a visual fraction model (area model, set model, or linear model) to show (a/b) x (c/d) and create a story context for this equation to interpret the product.

c. Multiply fractional side lengths to find areas of rectangles, and represent fraction products as rectangular areas.

d. Find the area of a rectangle with fractional side lengths by tiling it with unit squares of the appropriate unit fraction side lengths to show that the area is the same as would be found by multiplying the side lengths.
Unpacked Content
Evidence Of Student Attainment:
Students:
Given a fraction times a whole number,
  • use visual models to illustrate the product to develop the procedure (a/b) × q.
  • Create a story context for the equation (a/b) × q.
Given a fraction times a fraction,
  • Use visual models to illustrate the product to develop the procedure (a/b) × (c/d).
  • Create a story context for the equation (a/b) × (c/d).
Given a rectangle with two fractional side lengths,
  • Use an area model to illustrate and find the rectangular area.
  • Find the area by tiling it with unit squares of the appropriate unit fraction.
Given a rectangle with fractional side lengths including mixed numbers,
  • Use an area model to illustrate and find the rectangular area to lead to answers in the form of whole numbers or mixed numbers.

    • Example: Using an area model, a rectangle with dimensions of 1 1/2 x 1 2/3 will have partial products of 1, 1/2, 1/3, and 1/6 and the sum of the partial products will give an area of 2 sq units.
  • Use an area model to find the area of a rectangle by tiling the rectangle with unit squares.

    • Example: Using an area model, a rectangle with dimensions 1 1/2 x 1 1/3 will be tiled with unit squares of 1/6 size showing the tiled partial products as 6/6, 3/6, 2/6, and 1/6 for a total area of 12/6 sq units, so it would take 12 tiles of size 1/6 units to cover the area of the rectangle.
Teacher Vocabulary:
  • Fraction
  • Fraction model
  • Whole number
  • Area
  • Area model
  • Linear model
  • Set model
  • Tiling
  • Unit squares
  • Equation
Knowledge:
Students know:
  • How to write an equation involving repeated addition with fractions as a multiplication equation of a whole number times the fraction.
    Example: 2/9 + 2/9 + 2/9 + 2/9 = 4 x 2/9 = 8/9.
  • The relationship of partial products to an area model when multiplying by two whole numbers.
  • Area of a rectangle is determined by multiplying side lengths and is found in square units.
Skills:
Students are able to:
  • Use previous understandings of multiplication to
  • Find products of a fraction times a whole number and products of a fraction times a fraction.
  • Use area models, linear models or set models to represent products.
  • Create a story context to represent equations (a/b) × q and (a/b) × (c/d) to interpret products.
  • Find area of rectangles with fractional side lengths and represent products as rectangular areas.
  • Find the area of a rectangle by tiling the area of a rectangle with unit squares.
Understanding:
Students understand that:
  • Any whole number can be written as a fraction.
  • The general rule for multiplication involving fractions can be justified through visual models.
  • A variety of contextual situations can be represented by multiplication involving fractions.
  • Tiling with unit squares can be used to find the area of a rectangle with fractional side lengths.
Diverse Learning Needs:
Essential Skills:
Learning Objectives:
M.5.12.1: Define proper fraction.
M.5.12.2: Multiply fractions using denominators between 2 and 5.
M.5.12.3: Identify proper and improper fractions.
M.5.12.4: Recall basic multiplication facts.
M.5.12.5: Model changing a whole number to a fraction.
M.5.12.6: Partition a rectangle into rows and columns of same-size squares, and count to find the total number of them.
M.5.12.7: Label the numerator and denominator of a fraction.
M.5.12.8: Count the area squares for the length and width.
M.5.12.9: Identify the width and length of a rectangle.

Prior Knowledge Skills:
  • Solve real-word problems involving multiplication of fractions and mixed numbers.
  • Write equations to represent the word situation.
  • Use visual fraction models to represent the problem.
Alabama Alternate Achievement Standards
AAS Standard:
M.AAS.5.12 Determine the product of unit fractions with unlike denominators (limited to denominators of 2, 3, 4, 10) using visual models.
Mathematics
MA2019 (2019)
Grade: 5
14. Model and solve real-world problems involving multiplication of fractions and mixed numbers using visual fraction models, drawings, or equations to represent the problem.
Unpacked Content
Evidence Of Student Attainment:
Students:
  • Use a variety of strategies, including models, pictures, tables, and patterns to solve problems that provide a context for multiplying fractions and mixed numbers.
Teacher Vocabulary:
  • Fraction
  • Models
  • Mixed number
  • Multiplication
Knowledge:
Students know:
  • Contextual situations for multiplication.
  • How to use an area model to illustrate the product of two whole numbers and its relationship to partial products and extend this knowledge to illustrate products involving fractions and mixed numbers.
Skills:
Students are able to:
  • Solve real-word problems involving multiplication of fractions and mixed numbers.
  • Write equations to represent the word situation.
  • Use visual fraction models to represent the problem.
Understanding:
Students understand that:
  • A variety of strategies are used to model and solve problems that provide a context for multiplying fractions and mixed numbers.
  • Solutions are interpreted based on the meaning of the quantities and the context of the problem situation.
Diverse Learning Needs:
Essential Skills:
Learning Objectives:
M.5.14.1: Define improper fraction, mixed number, fraction, equations, numerator, denominator.
M.5.14.2: Multiply proper fractions with common denominators 2-10.
M.5.14.3: Solve problems using whole numbers.
M.5.14.4: Write number sentences for word problems.
M.5.14.5: Identify key terms to solve multiplication word problems.
Examples: times, every, at this rate, each, per, equal/equally, in all, total.
M.5.14.6: Recall basic multiplication facts.

Prior Knowledge Skills:
  • Divide unit fractions by a whole number and whole numbers by unit fractions.
  • Use visual models to illustrate quotients.
  • Create story contexts for division.
  • Use relationship between multiplication and division to explain quotients.
Alabama Alternate Achievement Standards
AAS Standard:
M.AAS.5.14 Use a model to solve multiplying a whole number by a unit fraction of 1/2, 1/3, and 1/4.
Mathematics
MA2019 (2019)
Grade: 5
15. Apply and extend previous understandings of division to divide unit fractions by whole numbers and whole numbers by unit fractions.

a. Solve real-world problems involving division of unit fractions by non-zero whole numbers and division of whole numbers by unit fractions and illustrate using visual fraction models, drawings, and equations to represent the problem.

b. Create a story context for a unit fraction divided by a whole number, and use a visual fraction model to show the quotient.

c. Create a story context for a whole number divided by a unit fraction, and use a visual fraction model to show the quotient.
Unpacked Content
Evidence Of Student Attainment:
Students:
  • Solve real-world problems involving division of a unit fraction by a non-zero whole number, or division of a whole number by a unit fraction.
  • Justify solutions using visual models, drawings, and equations to represent the problem context.
  • Explain quotients using the relationship between multiplication and division.
  • Create a story context for a unit fraction divided by a whole number and use models to illustrate the quotient.
  • Create a story context for a whole number divided by a unit fraction and use models to illustrate the quotient.
Teacher Vocabulary:
  • Unit fraction
  • Whole number
  • Division
  • Dividend
  • Divisor
  • Quotient
  • Equation
  • Multiplication
  • Factor
  • Fraction models
Knowledge:
Students know:
  • Contextual situations involving division with whole numbers and unit fractions.
  • Strategies for representing a division problem with a visual model.
Skills:
Students are able to:
  • Use previous understandings of operations to
  • Divide unit fractions by a whole number and whole numbers by unit fractions.
  • Use visual models to illustrate quotients.
  • Create story contexts for division.
  • Use the relationship between multiplication and division to explain quotients.
Understanding:
Students understand that:
  • A variety of contextual situations are represented with division of a whole number by a fraction or a fraction by a whole number.
  • Quotients resulting from division of a whole number by a fraction or a fraction by a whole number can be illustrated and justified with a visual model.
  • The relationship between multiplication and division can be used to justify quotients resulting from division of a whole number by a fraction or a fraction by a whole number.
Diverse Learning Needs:
Essential Skills:
Learning Objectives:
M.5.15.1: Define quotient.
M.5.15.2: Multiply a fraction by a whole number.
M.5.15.3: Recognize key terms to solve word problems.
Examples: times, every, at this rate, each, per, equal/equally, in all, total.
M.5.15.4: Recall basic multiplication and division facts.
M.5.15.5: Express whole numbers as fractions.
M.5.15.6: Recognize fractions that are equivalent to whole numbers.
M.5.15.7: Recall basic multiplication and division facts.
M.5.15.8: Solve word problems involving multiplication of a fraction by a whole number.
M.5.15.9: Recognize key terms to solve word problems.
M.5.15.10: Recall basic multiplication and division facts.

Prior Knowledge Skills:
  • Find products of a fraction times a whole number and products of a fraction times a fraction.
  • Use area models, linear models or set models to represent products.
  • Create a story context to represent equations (a/b) × q and (a/b) × (c/d) to interpret products.
  • Find area of rectangles with fractional side lengths and represent products as rectangular areas.
  • Find the area of a rectangle by tiling the area of a rectangle with unit squares.
Alabama Alternate Achievement Standards
AAS Standard:
M.AAS.5.15 Use a model to solve dividing a whole number by a unit fraction of 1/2.
Learning Objectives:

Students will be able to solve real-world problems involving multiplying and dividing fractions by a whole number by using visual models and equations.
  Strategies, Preparations and Variations  
Phase:
During/Explore/Explain, After/Explain/Elaborate
Activity:

Give each student a blank index card. Explain that they get to create a "Witches' Brew" using whatever disgusting ingredients they can imagine (fingernails, wolf hearts, eyeball juice, etc.). Their recipe will be enough to feed four witches. They must follow the guidelines:

    • You must use at least eight ingredients.

    • Each ingredient must be represented as a fractional amount.

After the students have created their recipe, they must figure out how much of each ingredient would be needed to make a brew to feed 12 witches (multiply amounts by three) and only one witch (divide amounts by four). A clever story keeps the students engaged -- for example, you might need a larger batch of the Brew because you're attending a broom convention, or you might need the one-serving version because your witch cousin is trapped inside a crystal ball and eats every meal alone.

The students should show the work of their calculations on paper. They can use models or equations, whichever they are more comfortable with.

If students finish early, they can draw a cauldron filled with their brew, including a visual representation of the correct amount of each ingredient.  

NOTE: Make sure students are going back to the original recipe amounts to perform their calculations.

In closing, ask questions such as:

  • Was it easier to multiply or divide the recipe?

  • How could we find the calculations using different operations?

  • How might this activity prepare you for the real world?
Assessment Strategies:

Assess students' final product to ensure they multiplied and divided fractions by a whole number correctly.
Advanced Preparation:

Gather index cards, one per student.  If students are illustrating, they will need white paper and coloring materials.
Variation Tips (optional):

Students can work with partners or in groups based on ability.  For a challenge, have students calculate the recipe for an odd number of witches, such as 18 (students will have to multiply by a fraction or break the calculation into parts).
Notes or Recommendations (optional):
 
  Keywords and Search Tags  
Keywords and Search Tags: divide, equation, fractions, Halloween, model, multiply