reSolve Bakery: Lesson 1

Australian curriculum number (ACMNA100)

Lesson abstract

In this lesson students calculate the number of cupcakes baked each day in a bakery with the cakes aligned in an 8 x 4 array. Students solve the problem using their own strategies and illustrate the strategies using the array. As the various strategies are shared, students reflect on the efficiency and ease of strategies and when the strategies would be appropriate. The opening string of arrays emphasises connections between multiplication facts.

Mathematical purpose (for students)

We can use arrays to help us multiply.

Mathematical purpose (for teachers)

The lesson focus is to build students’ flexibility with computation and representation, highlighting the importance of connecting symbols and arrays in mathematics. The lesson builds understanding of properties of multiplication by highlighting two main strategies: repeated doubling (based on the associative property) and strategies that partition numbers into convenient parts (based on the distributive property). Students will demonstrate a variety of stages of understanding of multiplication: from counting, to skip counting and repeated addition and then to full multiplicative understanding. The lesson provides assessment information as students’ chosen strategies reveal their understanding of and fluency with multiplication.