Mathematics / Year 6 / Number and Algebra / Fractions and decimals

View on Australian Curriculum website Australian Curriculum, Assessment and Reporting Authority
Curriculum content descriptions

Add and subtract decimals, with and without digital technologies, and use estimation and rounding to check the reasonableness of answers (ACMNA128)

  • extending whole-number strategies to explore and develop meaningful written strategies for addition and subtraction of decimal numbers to thousandths
  • exploring and practising efficient methods for solving problems requiring operations on decimals, to gain fluency with calculating with decimals and with recognising appropriate operations
General capabilities
  • Numeracy Numeracy
  • ICT capability Information and Communication Technology (ICT) capability
ScOT terms

Rounding,  Subtraction,  Addition,  Decimals



This is a website designed for teachers and students in year 5, and addresses components of the working with decimals topic. It is particularly relevant for comparison, addition, subtraction, multiplication and division with decimals. There are pages for both teachers and students. The student pages contain interactive ...


Sites2See – number for primary

Selected links to a range of interactive online resources for the study of number in Foundation to Year 6 Mathematics.


Summing Decimals

An interactive resource in which students learn how to add and subtract numbers that have up to two decimal places.


Adding decimals

This is a video demonstration, with audio commentary, of the procedure of adding decimal fractions. In the commentary, the presenter emphasises the links with the underpinning concepts of place value. Practice questions, limited to addition of decimal fractions involving tenths and hundredths, are presented with answers, ...


Decimals and fractions

This is a video demonstration of converting decimal fractions to simplified fractions. In the commentary, the presenter highlights the relevance of understanding and applying place value concepts, including the efficiency in initially interpreting the fractional part of the decimal fraction as a single fraction. Practice ...


Subtracting decimals

This is a video demonstration, with audio commentary, of the procedure for pen-and-paper subtraction of decimal fractions. In the commentary, the presenter emphasises the links with the underpinning concepts of place value. Practice questions, limited to subtraction of decimal fractions involving tenths and hundredths, ...


Decimal multiplication: petrol prices

Petrol for our cars is made from crude oil. The price of crude oil is constantly changing. This affects the price of petrol at the pump. Listen to Natasha Thiele explain how and why the price of petrol keeps changing. This clip provides context for decimal multiplication.


Mapping a sea voyage: calculating distance

Scientists involved in the Two Bays Project describe data collection methods for their 20-day expedition around Port Phillip and Western Port bays. Watch this clip to view the route mapped out by the scientists. Use Google Maps to recreate the route and calculate the total distance travelled.


Wishball: hundredths

Test your understanding of decimal place value with numbers that include hundredths. Receive a starting number, such as 46.87, and work towards turning it into a target number, such as 85.32. Spin a random digit, choose its decimal place value and decide whether to add or subtract the random digit from your starting number. ...


The foul food maker: go figure

This tutorial is suitable for use with a screen reader. It explains how the use of simple words can describe the likelihood of everyday events. How likely is an event: certain, likely, equal chance, unlikely or certainly not? Answer some questions using these words and then build your own examples. Learn how to describe ...


Playground percentages

Help a town planner to design two site plans for a school. Assign regions on a 10x10 grid for different uses such as a playground, canteen, car park or lawn. Calculate the percentage of the total site used for each region. Use a number line to display fractions and equivalent fractions.


Fraction fiddle: hit the apple

Help an archer to hit an apple with his arrow. Build two fractions to make a total of one whole. Complete the numerators of both fractions (they may have fixed denominators). For example, work out how many quarters and how many eighths can be added together to total one whole. Look at fraction bars and a number line to ...


Small scale measurements

What units of measurements do we use to describe incredibly small things like blood cells and atoms? Watch as you are taken on a journey to explain the different units of measurement that we use to describe the very small.


Primary mathematics: open-ended tasks

These seven learning activities, which focus on 'open-ended tasks' using a variety of tools (software) and devices (hardware), illustrate the ways in which content, pedagogy and technology can be successfully and effectively integrated in order to promote learning. In the activities, teachers use investigations in order ...


TIMES Module 18: Number and Algebra: decimals and percentages - teacher guide

This is a 21-page guide for teachers containing an introduction to decimals and percentages. It shows how place value is extended to describe positive numbers less than one. It also explores how to represent decimals on the number line, compare decimals, undertake the four basic arithmetic operations with decimals and change ...


TIMES Module 7: Number and Algebra: addition of whole numbers - teacher guide

This is a 16-page guide for teachers. This module introduces addition of whole numbers.


TIMES Module 8: Number and Algebra: subtraction of whole numbers - teacher guide

This is a 16-page guide for teachers. This module continues the consideration of whole numbers.


Imperial pie

This activity involves making a cake using a recipe in which the quantities of the ingredients required are measured using a variety of imperial units. To complete the recipe, students need to convert the imperial units to metric units in order to be able to use their metric measuring instruments. The activity serves to ...


Ordering Decimals

An animated tutorial about ordering numbers with up to 3 decimal places. An interactive quiz is included.


reSolve: Reconciliation data

This lesson prompts students to examine data from the Reconciliation Barometer report, collect their own local data and compare with the national findings. Students discuss the meaning of reconciliation, explore statements from Reconciliation Barometer report, design a survey to collect local data relating to the statements ...