The addition mat is primarily used to help children develop the concept of addition which is the joining of groups together to find a total. However this resource can also be used to demonstrate the concept of subtraction.
The concept of subtraction is when you know the total and one part of the total, and you have to find the other part (Jamieson-Proctor, 2014). The addition mat becomes a subtraction mat and can be used to demonstrate this by taking away tennis balls from the large area and counting how many are left if a number is taken away. It can also be used to demonstrate comparison subtraction by having, for example, four tennis balls in one section and three in another section to come up with the difference. A third type of subtraction is putting ,for example, five balls in one section of the tennis court and saying I would like to have three and counting back how many more I would need to have five.
The following is taken from the ACARA website (2013), and it outlines what strand, sub-strand and elaborations that the use of this resource covers:
Foundation Year: Represent practical situations to model addition and sharing (ACMNA004)
- Using a range of practical strategies for adding small groups of numbers, such as visual displays and concrete materials.
- Using Aboriginal and Torres Strait Islander methods of adding, including spatial patterns and reasoning.
Year 1: Represent and solve simple addition and subtraction problems using a range of strategies including counting on, partitioning and rearranging parts (ACMNA015)
- Developing a range of mental strategies for addition and subtraction problems.
Year 2: Explore the connection between addition and subtraction (ACMNA029)
- Becoming fluent with partitioning numbers to understand the connection between addition and subtraction.
- Using counting on to identify the missing element in an additive problem.
This resource would be used with children in the foundation year, year 1 and year 2 of primary school, therefore children aged 5 to 7 (ACARA 2013).
This particular resource fits in at the children’s language stage of the language model in terms of subtraction. After using the addition mat students should be able to demonstrate the three types of subtraction and explain the reasoning behind the concept of subtraction.
Australian curriculum, assessment and reporting authority. (2013) in EDX1280 Foundations in Numeracy, course notes. Toowoomba; University of Southern Queensland.
Australian curriculum, assessment and reporting authority. (2013). School structures, ACARA. Retrieved March 30, 2014, from http://www.acara.edu.au/reporting/national_report_on_schooling/schools_and_schooling/school_structures.html
Jamieson-Proctor, R.(2014). EDX1280 Foundations in Numeracy, course notes. Toowoomba; University of Southern Queensland.