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Listed under:  Mathematics  >  Number (Mathematics)  >  Number operations  >  Subtraction
Video

Numbers Count: Adding two numbers

How many different ways can you think of to add two numbers to reach ten? Watch this video to learn them all!

Video

Count Us In, Ep 5: Cool ways to count 1 to 5

Watch Dodly and Flynn at the monster fair investigating ways of representing the numbers from one to five. Two is a double, such as in a double scoop of ice-cream. Tally marks and 'tri' are used as representations of three, while four monster apples are shown as 3 and 1 or 2 and 2.

Video

What is a quarter?

What is a quarter? You get quarters when you divide a whole into four equal parts. Each one of these four parts is a quarter. Watch this great explainer produced by Monique in collaboration with ABC Splash and see how she explains quarters.

Video

Musical fractions

Break down a song by counting how long the notes are in action! Learn about patterns in rhythms and musical notes, and discover the role of fractions in denoting whole, half and quarter notes and creating distinct sounds.

Video

BTN: What is the GST?

The Goods and Services Tax (GST) is a tax placed on things people buy with money or things people do for money. Can you name some goods and services that have GST? What about some goods and services that don't have GST? Find out when and why the GST was first introduced.

Online

reSolve: Algebra: Triangle Inequality

This sequence of two lessons explores the triangle inequality theorem. Students are challenged to construct triangles with a given number of matchsticks, explore and record what combinations of sticks can create valid triangles and represent their findings using mathematical expressions. Each lesson is outlined in detail ...

Interactive

Equivalent linear algebraic expressions

This is a six-page HTML resource about solving problems concerning equivalence of linear algebraic expressions. It contains one video and four questions, three of which are interactive. The resource discusses and explains equivalence of linear algebraic expressions to reinforce students' understanding.

Video

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, ...

Video

Fractions in the real world

How many quarters make up a whole? Watch this video to find out how else you can represent 2/4 and how to add up quarters to make a whole.

Online

reSolve: Algebra - Equivalence

This sequence of two lessons builds students' understanding of equivalence as balance. The equals sign is used to indicate the same value on both sides of an equation. Students develop their understanding of equivalence by looking at balancing scales with blocks of different weights. Each lesson is outlined in detail including ...

Interactive

Wishball: whole numbers

Test your understanding of decimal place value with whole numbers. Receive a starting number, such as 3786, and work towards turning it into a target number, such as 7664. Spin a random digit, choose its decimal place value and decide whether to add or subtract the random digit from your starting number. You can use a 'Wishball' ...

Online

reSolve: Algebra: Odds and Evens

This sequence of two lessons focuses on developing students' understanding of the properties of odd and even numbers. Students explore the results of adding and subtracting odd and even numbers and use these results to make generalisations. They then apply this generalisation to solve problems and to explore patterns. The ...

Online

reSolve: Algebra: Chess - The King

This lesson aims to build students' algebraic reasoning and understanding of number as they explore computation on the number chart. Students explore the moves of a king chess piece and how the value of the numbers change as he moves. This builds into an algebraic exploration of equivalent values that can be found on the ...

Online

reSolve: Addition: Chess - The Rook

This lesson engages students in investigating place value and the addition and subtraction of numbers by exploring computation on the number chart. Students analyse the moves of a rook chess piece and how the value of the numbers change as he moves. This builds into an exploration of how the number chart can be used as ...

Online

reSolve: Algebra: Number Sequences

This sequence of lessons aims to build students' algebraic thinking through explorations of additive number patterns. Students are challenged to solve problems to generate patterns, explore strategies for addition and subtraction and apply their skills to constructing their own new patterns.The lessons are outlined in detail ...

Online

reSolve: Authentic Problems: What's For Lunch?

This sequence of four lessons invites students to investigate how many of a chosen food item are eaten at their school in a year. Students identify the mathematical knowledge they need to find how many of the selected items they eat in a year and devise a plan to find the total number, using grouping, partitioning and repeated ...

Online

reSolve: Addition: Partitioning

This sequence of two lessons explores early algebraic thinking around the concept of equivalence. Students develop equivalence understanding by partitioning numbers into two parts. They explore the commutative property and compensation as they are challenged to find all possible combinations. Each lesson is outlined in ...

Online

reSolve: Lamingtons

This sequence of three lessons explores the mathematical idea that fractions represent division. In the first lesson, students are invited to solve a problem involving fair sharing of different plates of lamingtons. Students explore how the denominator represents how many shares and the numerator represents the number being ...

Interactive

The difference bar: generate easy subtractions

Learn how to split up numbers in your head. Use a linear partitioning tool to help find the difference between pairs of two-digit numbers such as 25 and 34. In these examples, the difference is always less than ten. Split the numbers into parts that are easy to work with, work out each part and then solve the original calculation.

Interactive

Wishball challenge: hundreds

Challenge your understanding of place value in whole numbers up to 999. Receive a starting number, such as 328, and work towards turning it into a target number, such as 177, within 20 turns. Spin a random digit, choose its decimal place value and use the given operation (either addition or subtraction) on your starting ...