Grade 3: "Doggy Treats"
(From: OAME)
2 Day Lesson
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Number
B1. demonstrate an understanding of numbers and make connections to the way numbers are used in everyday life
B1.7 represent and solve fair-share problems that focus on determining and using equivalent fractions, including problems that involve halves, fourths, and eighths; thirds and sixths; and fifths and tenths
B2. use knowledge of numbers and operations to solve mathematical problems encountered in everyday life
B2.7 represent and solve problems involving multiplication and division, including problems that involve groups of one half, one fourth, and one third, using tools and drawings
Social Emotional Learning Skills (SEL) in Mathematics and the Mathematical Processes
A1. Throughout this grade, in order to promote a positive identity as a math learner, to foster well-being and the ability to learn, build resilience, and thrive, students will apply, to the best of their ability, a variety of social-emotional learning skills to support their use of the mathematical processes and their learning in connection with the expectations in the other five strands of the mathematics curriculum.
In this lesson, to the best of their ability, students will learn to think critically and creatively as they apply the mathematical processes reasoning and proving (develop and apply reasoning skills (e.g., classification, recognition of relationships, use of counter-examples) to justify thinking, make and investigate conjectures, and construct and defend arguments), selecting tools and strategies (select and use a variety of concrete, visual, and electronic learning tools and appropriate strategies to investigate mathematical ideas and to solve problems), and communicating (express and understand mathematical thinking, and engage in mathematical arguments using everyday language, language resources as necessary, appropriate mathematical terminology, a variety of representations and mathematical conventions), so they can make connections between math and everyday contexts to help them make informed judgements and decisions.
divide materials or objects into fractional parts to solve fair share problems.
divide the object (jerky) into equal parts.
represent the problem using pictures or diagrams.
represent the problem using numbers or words.
use mathematical language to describe fractions.
Image of Beef jerky
Strips of paper available for students
At home: Prior to the lesson, suggest to parents that they have a few strips of paper available for their child to use.
Students at home or in school may use the images contained in the Sharing Doggie Treats slides to solve the problems and communicate their solutions.
Students have already
Represented fractions using concrete materials.
Worked with different fraction representations (eg: area model, linear model, and set model).
Knowledge of fraction words such as halves, fourths, thirds, sixths, fifths, eighths, and tenths.
Display an image of Beef Jerky and ask the students what they see. Have them share any experiences they have had eating or making jerky. You may wish to note that jerky is similar to dried foods like pemmican that were very important for many Indigenous peoples as well as early European traders.
Explain that jerky can also be a treat for dogs, as long as it is made for dogs, not people. Then introduce Adrianna who runs a doggie day care centre and who makes long strips of jerky for the dogs who stay with her. This morning, Adrianna has 12 strips of jerky ready for the dogs, and eight dogs arrive at her centre.
Pose the question: How much jerky does each dog get today ? How do you know ?
Guide students to the availability of paper strips that may be used as a tool.
Encourage the students to turn and discuss the problem with a partner.
Summarize the discussion to ensure students understand:
- that fair sharing requires equal parts,
- there is more than one way to describe or represent the amount of jerky each dog gets,
- there are many strategies for solving this problem.
Day 1
Form pairs of students to complete the following task.
Present the scenario:
On another day, Adrianna has prepared 10 pieces of jerky. Six dogs arrive. How can she share the jerky between the dogs?
Have the students solve the problem and record their solutions on chart paper. Encourage them to use a diagram as well as numbers to represent the solution. Circulate as the students complete the task.
Have the students form groups of four and compare their strategies and solutions.
Have the students complete an exit ticket with the following problem:
Before she shares the jerky, Adrianna cuts each of the ten strips into six pieces. How many little pieces of jerky does each dog get? What fraction of a whole strip is one piece?
Day 2
Display a completed solution (or solutions) from day one that shows a correct solution. Have the students who submitted that solution describe their thinking. Discuss the exit ticket with the students. Explore the link between division and fractions.
Next step: Tell the students that today they will be helping Adrianna once again. Form pairs of students to complete the following task.
Present the scenario:
This time Adrianna has prepared four pieces of jerky. Five dogs arrive. How can she share the jerky between the dogs ?
Have the students solve the problem and record their solutions on chart paper. Ask them to use a diagram as well as numbers to represent the solution.
Circulate as the students complete the task.
Collect students’ work to prepare for consolidation.
Teacher Moves
Have students rephrase the problem in their own words.
Ask students:
“What are we looking for in this problem ?”
“Do you need more information or do we have enough information? How do you know ?”
“How is this problem similar to the previous problem ? What is different ?
“What tool or tools might help you solve this problem ?”
As you circulate, ask students about the mathematical processes they are using/could be using:
“How do you know your answer makes sense ?”
“How can you use mathematical language to describe your thinking ?”
“How do you know each dog got an equal share ?”
“What tool or tools did you use ? How did they help ?”
“What is another way to describe this ?”
"How do we write those fractions?"
While students work on the problem, circulate and ask questions or offer prompts to support their learning:
“What are we looking for in this problem ? How is it similar to yesterday’s problems ? How is it different from yesterday’s problems ?”
“Do you need more information or do we have all we need ? How do you know ?“
“What tool or tools might help you solve this problem ?”
“How do you know this answer makes sense ?”
“How can you use mathematical language to describe your thinking ?”
“How do you know each dog got an equal share ?”
DAY 1:
Opportunities for Differentiation
Parallel tasks:
For students who would benefit from more experience working with halves, provide the following problem: two dogs share five pieces of jerky.
For students who would benefit from a more challenging experience provide the following problem: five dogs share 14 pieces of jerky.
Offer students paper strips that may be used as a tool.
If students who are solving the six dogs, ten strips of jerky scenario tend to focus on making halves, ask them to consider other sharing quantities e.g., “ You made two (or four) pieces. What other ways could you divide the strip?”
Opportunities for Assessment
Ask students to explain the strategies they are using. How does this strategy help ? What makes it hard to use ?
Note their ability to explain the reasoning behind the strategies they try.
Make anecdotal notes of actions such as:
Verbalizes the problem
Tries multiple strategies
Checks the reasonableness of the solution
Use fractional language
Communicates ideas orally, gesturally, and in written form
Records thinking so others can understand the solution.
Students online may wish to use slides from Sharing Doggie Treats to help them solve the problems and communicate their thinking.
DAY 2:
Opportunities for Differentiation
Let students discuss the exit ticket with a partner before completing the task.
For students who completed a parallel task, review the premise of the exit ticket, that is, 10 strips each cut into six pieces shared between six dogs.
Parallel tasks:
For students who worked with the half problem on day one provide the following problem to work with thirds: three dogs share four pieces of jerky.
For students who would benefit from a more challenging problem provide the following problem: seven dogs share five pieces of jerky. Be sure they use a visual as well as numeric representation to explain their thinking.
Opportunities for Assessment
Ask students to explain the strategies they are using. “How does this strategy help ? What makes it hard to use ?” Note their ability to explain the reasoning behind the strategies they try.
Make anecdotal notes of actions such as:
Verbalizes the problem
Tries multiple strategies
Checks the reasonableness of the solutions
Can describe the solution
Records thinking so that others can interpret the information
Uses fractional language to explain thinking
Be aware of students' ability to explain the reasoning behind the strategies they tried.
Use the Bansho technique to display all the solutions the students developed, organized by strategies used. Students have the opportunity to see and hear many approaches. Help them realize that the same strategies can be used with different starting numbers and with improper and proper fractions. What strategies are similar? How are they different ?
Do you see a method that makes sense to you even if it is different from your own ?
Which strategy would you use if you solved another problem like this again ?
How did this strategy help you ? What made it difficult to use ?
Do you see a method that is different from your own that you like better ? Why do you like it better ?
How do you know this solution is accurate ?
How can we tell that different-looking answers are equally correct ?
How could you prove that this answer is right ?
What fraction of a strip is one small piece? How do you know ? (If you have parallel tasks displayed ask: Why is there a different fractional value for this problem ?)
Compare a solution from day 1 and one from day 2 that use the same strategy (e.g., cut all the strips into small pieces before doing a one to one fair share). Explore the similarities and differences between the fractional amounts and how they are represented and described.
Assessments as, for and of learning are embedded throughout the lesson.
SEL Self-Assessments (English) and Teacher Rubric
At another time, discuss with the students:
“Why must all pieces be the same size?”
“When might Adrianna decide to share the jerky unfairly?”
“When is fair sharing important in your life?”
“When might we get unequal shares?”
Encourage them to recognize the links between the math task and real life. How does thinking about imaginary dog jerky help them consider fairness in the class, the family, the community, or the wider world ?
Have the class brainstorm ideas together based on the sentence stem “I have to share when….” Then have them reflect on which sharing examples require equal sharing. Then discuss how the sharing makes them feel ? How do they cope when they don’t want to share but are required to do so ? Is sharing always important? When does it really matter ? When is it ok not to share ?
Have the students try a further doggie day care task - this time Adrianna is sharing 12 dog biscuits amongst four dogs. What fraction of the biscuits does each dog get ? What if she has 13 biscuits or 14 biscuits ?
Read aloud stories based on fair sharing. As you read the book, think aloud using fractional language, noting the importance of equal units, etc. Two possible stories available in print and online are The Doorbell Rang by Pat Hutchins or The Lion’s Share by Matthew McElligott, but there are many others.