More lollies

Achievement Objectives
NA1-1: Use a range of counting, grouping, and equal-sharing strategies with whole numbers and fractions.
Student Activity

On Monday, Sam and Sylvia have 7 lollies.
They are not equally shared.
2 of the lollies are Sam's.
How many lollies are Sylvia's?

Sam has the same number of lollies each day up to (and including) Friday.
Altogether Sam and Sylvia have 20 lollies.
How many lollies are Sylvia's that week?

Specific Learning Outcomes

Solve problems up to 20 using subtraction and addition.

Description of Mathematics

Students apply addition strategies to solve this problem.

This is one of six problems: Lollies! (Level 1), More Lollies (Level 1), Sharing Lollies (Level 2), Lollies, Lollies, Lollies (Level 3) and Still More Lollies (Level 4), which become more algebraic in their focus at each level.

Activity

The Problem

On Monday, Sam and Sylvia have 7 lollies. They are not equally shared. 2 of the lollies are Sam's. How many lollies are Sylvia's?

Sam has the same number of lollies each day up to (and including) Friday. Altogether Sam and Sylvia have 20 lollies. How many lollies are Sylvia's that week?

Lesson Sequence

  1. Review the days of the week. 
  2. Pose the problem to the class and have students retell in their own words what they have to find out.
  3. Have students suggest how they might record/show their solutions.
  4. As the students work on the problem (in pairs or individually) as them to explain their thinking.
    How did you start the problem?
    What have you found out?
    Are you convinced that you are correct?
    Can you convince me?
  5. Share solutions.

Other Contexts

Use items of current interest to pose similar problems.  

Extension 

When combined and then shared fairly at the end of four days, Sam and Sylvia each get 6 lollies. If Sam has 2 lollies each day, how many does Sylvia have each day?

Vary the number of days, number of lollies each and fair share amounts.

 

Solution

Students may use a range of representations to show that:

7 - 2 = 5. Sylvia has 5 lollies.

On 5 days Sam has 2 + 2 + 2 + 2 + 2 = 10 lollies. So Sylvia has 20 – 10 = 10 lollies.

Extension solution

6 lollies each is 12 altogether. Sam has 2 + 2 + 2 + 2 = 8. Sylvia has 12 - 8 = 4, which is 1 lolly each day.

Attachments
HeRare2.pdf193.93 KB

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