# Multi-age 3–6, mathematics, Year B – Unit 15

This multi-age unit develops the big idea that addition and subtraction problems can be solved using a variety of strategies.

## Syllabus

Outcomes and content descriptors from Mathematics K–10 Syllabus (2022) © NSW Education Standards Authority (NESA) for and on behalf of the Crown in right of the State of New South Wales, 2024.

In this 2-week unit, students are provided opportunities to:

• partition, rearrange and regroup numbers to at least 1000 to solve additive problems (Stage 2)
• choose and use efficient strategies to solve addition and subtraction problems, including decimals and percentages (Stage 3)
• select and apply known strategies to flexibly add and subtract large numbers and decimals, including in rich real-world tasks.

## Syllabus focus area and content groups

### Stage 2

#### Representing numbers using place value A – MAO-WM-01, MA2-RN-01

• Whole numbers: Read, represent and order numbers to thousands
• Whole numbers: apply place value to partition and regroup numbers up to 4 digits

#### Representing numbers using place value B – MAO-WM-01, MA2-RN-01

• Whole numbers: Apply place value to partition, regroup and rename numbers up to 6 digits
• Whole numbers: Recognise and represent numbers that are 10, 100 or 1000 times as large

#### Additive relations A – MAO-WM-01, MA2-AR-01, MAR-AR-02

• Use the principle of equality
• Recognise and explain the connection between addition and subtraction
• Select strategies flexibly to solve addition and subtraction problems of up to 3 digits
• Represent money values in multiple ways

#### Additive relations B – MAO-WM-01, MA2-AR-01, MA2-AR-02

• Partition, rearrange and regroup numbers to at least 1000 to solve additive problems
• Apply addition and subtraction to familiar contexts, including money and budgeting
• Complete number sentences involving additive relations to find unknown quantities

### Stage 3

#### Represents numbers A – MAO-WM-01, MA3-RN-02

Decimals and percentages: Recognise that the place value system can be extended beyond hundredths

#### Representing numbers using place value B – MAO-WM-01, MA2-RN-03

• Decimals and percentages: Make connections between benchmark fractions, decimals and percentages
• Decimals and percentages: Determine percentage discounts of 10%, 25% and 50%

#### Additive relations A – MAO-WM-01, MA3-AR-01

• Apply efficient mental and written strategies to solve addition and subtraction problems
• Use estimation and place value understanding to determine the reasonableness of solutions

#### Additive relations B – MAO-WM-01, MA3-AR-01

• Choose and use efficient strategies to solve addition and subtraction problems
• Applies known strategies to add and subtract decimals

#### Non-spatial measure B – MAO-WM-01, MA3-NSM-02

Time: Solve problems involving duration, using 12- and 24-hour time

Category: