Introduction

• finding the number of slices that were sold by starting at $32.50 and repeatedly subtracting $1.25 untilthey get to 0, then counting the number of times they subtracted $1.25. Knowing the number of slices,students can then find the number of pizzas;• determining that the price of one pizza is $5.00 (by adding $1.25 + $1.25 + $1.25 + $1.25), recognizingthat the price of 6 pizzas is $30.00, then including the price of an additional half pizza to get to $32.50.Reflecting and ConnectingInstructional Grouping: Whole classReconvene the students. Ask a few pairs to present their problem-solving strategies and solutions to theclass. Attempt to include presentations that show various strategies.As students explain their work, ask questions that encourage them to explain the reasoning behind theirstrategies.• “How did you find the number of pizzas that the class sold?”• “Why did you use this strategy?”• “What worked well with this strategy? What did not work well?”• “How do you know that your solution makes sense?”Following the presentations, encourage students to consider the effectiveness and efficiency of thevarious strategies that have been presented. Ask the following questions:• “In your opinion, which strategy worked well?”• “Why is the strategy effective in solving this kind or problem?”• “How would you explain this strategy to someone who has never used it?”• “How did students represent fractional amounts? How did these representations help to solve theproblem?”• “How did students do computations with money amounts? How did these computations help tosolve the problem?”AssessmentThroughout the lesson, observe students to assess how well they:• represent fractional amounts, using concrete materials, diagrams, and symbolic notation;• read and write money amounts;• select and apply appropriate problem-solving strategies;• add and subtract money amounts.Use assessment information gathered in this lesson to determine subsequent learning activities.Home ConnectionAsk students to solve the following problem at home:Two pizzas are the same size and have the same toppings. The first pizza is cut into fourths, and eachslice costs $1.95. The other pizza is divided into sixths, and each slice costs $1.25. Which pizza costsmore?Encourage students to share with a family member how they solved the problem.58 A Guide to Effective Instruction in Mathematics, Kindergarten to Grade 6 – Volume One