find unknown values in numerical equations involving addition and subtraction, using the properties of numbers and operations

How Bloomi helps with this

This is a readiness-year topic that builds towards the next NAPLAN year. Bloomi practises it as curriculum mastery, never test drilling.

What this looks like in the classroom

• demonstrating the commutative properties of addition using materials, diagrams and number lines; for example, using number lines to demonstrate that \(5 + 2 = 2 + 5\), demonstrating that \(2 + 2 + 3 = 7\) and \(2 + 3 + 2 = 7\) and \(3 + 2 + 2 = 7\)
• using balance scales and informal uniform units to create addition or subtraction number sentences showing equivalence, such as \(7 + 8 = 6 + 9\), and to find unknowns in equivalent number sentences, such as \(6 + 8 = \square + 10\)
• using relational thinking and knowledge of equivalent number sentences to explain whether equations involving addition or subtraction are true; for example, explaining that \(27 \space– \space 14 = 17\space – \space4\) is true and using a number line to show the common difference is \(13\)