AC9M3A01 Year 3 Mathematics

This Content Descriptor from Year 3 Mathematics provides the specific knowledge and skills students should learn. Use it to plan lessons, create learning sequences, and design assessments that align with the Australian Curriculum v9.

recognise and explain the connection between addition and subtraction as inverse operations, apply to partition numbers and find unknown values in number sentences

Elaborations

• 1 partitioning numbers using materials, part-part-whole diagrams or bar models, and recording addition and subtraction facts for each representation, explaining how each fact is connected to the materials, diagrams or models; for example, \(16 + 8 = 24\), \(24\space – \space8 = 16\), \(8 = 24 \space–\space 16\)
• 2 using the inverse relationship between addition and subtraction to find unknown values with a calculator; for example, representing the problem, “Peter had some money and then spent \(\$375\), now he has \(\$158\) left. How much did Peter have to start with?” as \(\square – \$375 = \$158\) and solving the problem using \(\$375 + \$158 = \$533\); solving \(27 + \square = 63\) using subtraction, \(\square = 63\space – \space27\) or by counting on; \(27, 37, 47, 57, 60, 63,\) so add \(3\) tens and \(6\) ones, so \(\square = 36\)
• 3 exploring First Nations Australians’ stories and dances that show the connection between addition and subtraction, representing this as a number sentence and discussing how this conveys important information about balance in processes on Country/Place

Related Achievement Standards