# Multiplication: Domino Arrays

Australian curriculum number (ACMNA056; ACMNA057)

This sequence builds students’ multiplicative thinking through the use of arrays, whereby all parts of the array are not visible. Students are encouraged to find the total number of items in an array by multiplication rather than counting by 1s or skip counting. The tasks connect area, arrays and multiplication.

This sequence is for students who:

• have used arrays where all parts of the array can be seen to help solve multiplication problems.
• are starting to build knowledge of their multiplication facts up to 10 x 10.
• are familiar with measuring the area of a flat surface by covering with a common unit, without leaving gaps or overlapping.

### Lesson 1: Which Uses The Most?

Students explore the number of dominoes required to cover a rectangle. They are presented with four domino designs, which are placed in different orientations. As the students work through the problem, they realise that the same number of dominoes will be used regardless of orientation. Students are then asked to explain why the same number of dominoes is used.

### Lesson 2: Six Arrays

Students investigate six arrays that have been covered by dominoes. They are asked to record what they notice about the arrays. They are presented with four observations by other children and match each observation to their relevant arrays.

Last updated June 14 2020.