Year level: 4

Strand: Number

Lesson length: 60 mins

In this lesson, students investigate the properties of odd and even numbers. They use their discoveries to confirm calculations involving addition, subtraction and multiplication.

### Achievement standard

Students use the properties of odd and even numbers. Students use their proficiency with addition and multiplication facts to add and subtract, multiply and divide numbers efficiently.

### Content descriptions

Students explain and use the properties of odd and even numbers ACM9M4N02

Students develop efficient strategies and use appropriate digital tools for solving problems involving addition and subtraction, and multiplication and division where there is no remainder AC9M4N06

Students recall and demonstrate proficiency with multiplication facts up to 10 x 10 and related division facts; extend and apply facts to develop efficient mental strategies for computation with larger numbers without a calculator AC9M4A02

### General capabilities

Numeracy

Critical and Creative Thinking

• Analysing: interpret concepts and problems, draw conclusions, and provide reasons.
• Generating: consider alternatives.
• Inquiring: identify, process and evaluate information.

This lesson is an explorative task. Observe students as they undertake the task. Use questioning and feedback to support learning.

• Does the student use a systematic approach to recording their investigation? Do they need support in creating a table?
• Does the student go beyond addition and include other operations of multiplication, subtraction, and division? Are the mathematical operations carried out accurately? Do they require clarification and support for any of the mathematical operations? What feedback do they require to improve their understanding?

It is expected that students can:

• identify odd and even numbers and explain the difference between them
• add, subtract and multiply numbers and identifies the ÷ and × symbols
• begin to construct arguments and provide elements for choices made.

Some students may:

• find it challenging to understand the difference between 2 groups and 2 in each group. Support students to use materials to model splitting amounts into 2 groups
• have limited number fact knowledge to solve equations involving additive thinking and multiplication.
• be confused about the properties of 0 – odd or even. Even – any number divided by 2 to create another whole number. Half of zero = zero. Odd numbers on either side or 0 e.g. –1 and 1
• refer to the whole number and the digits it contains rather than focusing on the last digit (ones) to support recognition e.g. when zero is a digit in the number. Refer to physical models, definitions, 100s chart to recognize pattern and use this to confirm.
• be confused about even number identification when the number includes an odd amount of digits e.g. 732 – 3 digits so the number is made up of an odd number of digits but is an even number
• not be familiar with testing conjectures. Understanding that a conjecture is a statement that could be true or false. Support students to understand that they need to collect evidence to confirm if the conjecture is true.

## What you need:

• Lesson plan (Word)

• Teacher’s slides (PowerPoint)

• Testing conjectures sheet (Word)

• Pre-prepare physical materials (manipulatives) to allow students to perform mathematical processes involving the operations of addition, subtraction, multiplication and division.