Moira’s Birthday - Primary

Introduction:

• Prepare a jar of small items before starting the lesson (see materials).
• Show students the jar of items lesson and ask them to estimate the number of items in it. Ask what strategies they use for estimating quantities.
• Invite students to share their understanding of the word “estimation”.
  • An estimate is a number that is reasonably close to the right answer. Estimation is a powerful tool for planning because it can help you quickly determine a numerical quantity that is close to the answer.
• Ask students the following questions to support their understanding of estimation.
  • Have you ever estimated anything? What do we estimate? (e.g. costs, temperature, distances, amounts)
  • Can you estimate the number of students in our class without counting?
• Ask students whether they have helped plan a party before. Potential discussion questions include:
  • How many people were invited to the party?
  • What type of food was served at the party?
  • How much food do you estimate was needed for the party? (e.g., Can you estimate how many slices of pizza were needed for all the party guests?)
• Read Moira’s Birthday to the class.

Activity:

• After reading the story, inform students that they will be helping Moira plan a new birthday party.
• Students will work through different scenarios to help Moira plan her party. Present the slideshow (Appendix A) and read the scenario on the first slide.
• Suggest to students that they think about their answers before sharing, but should take too much time because the objective is to quickly estimate quantities.
  • Read the “speaker notes” underneath the slides for potential responses.
• Work through the scenarios on each of the slides using the same procedure.

Conclusion:

• Discuss the various strategies that students used to estimate quantities. Ask students to share their new understandings of estimation as a tool for planning.