Number Sense Activities for Foundation to Year 2

Number Sense: The Foundation of All Mathematics

Number sense is the intuitive understanding of numbers — what they mean, how they relate to each other, and how they behave when we operate on them. It is widely regarded as the single most important foundation for all later mathematical learning. Children with strong number sense don't just memorise facts; they understand why 7 + 3 = 10, they can see that 8 is close to 10 but 3 is not, and they know that if you take some away from a group, you have less than you started with.

For students in Foundation to Year 2, developing number sense is the central goal of mathematics instruction. The Australian Curriculum v9 Number strand places heavy emphasis on counting, subitising, number recognition, and understanding the structure of numbers in these early years — and research consistently shows that the strength of a child's number sense in the first years of school is one of the strongest predictors of their mathematical achievement in later years.

This page brings together practical activities, teaching advice, and ready-to-use resources to help Australian teachers and parents build strong number sense in young learners.

Number sense is a broad term that encompasses several interconnected skills. In the early primary years, the key components are:

Counting

Counting is far more complex than it appears. True counting involves several distinct skills:

• Rote counting — reciting the number sequence in order (one, two, three, four...)
• One-to-one correspondence — matching exactly one number word to each object being counted
• Cardinality — understanding that the last number counted tells you how many there are in total
• Conservation — knowing that the number of objects in a group stays the same regardless of how they are arranged

Subitising

Subitising is the ability to instantly recognise how many objects are in a small group without counting them one by one. When you glance at a dice face showing five dots and immediately know it's five, you're subitising. There are two types:

• Perceptual subitising — instantly recognising small quantities (1–4) at a glance
• Conceptual subitising — recognising larger quantities by seeing them as groups (e.g., seeing 6 as two groups of 3)

Subitising is foundational because it builds the mental images of numbers that children draw on for addition, subtraction, and understanding number relationships.

Number Recognition

Number recognition means being able to read and write numerals (the written symbols 0–9) and connect them to the quantities they represent. This includes:

• Identifying written numerals
• Writing numerals correctly
• Matching a numeral to a quantity (e.g., seeing "5" and knowing it means five objects)

Number Ordering and Comparing

Understanding that numbers have a fixed order and that some quantities are more or less than others. This includes:

• Ordering numbers from smallest to largest (and vice versa)
• Comparing two quantities using language like "more than", "less than", "the same as"
• Understanding "before" and "after" in the number sequence

Number Bonds

Number bonds (also called part-part-whole relationships) describe how numbers can be broken into parts. For example, 7 can be split into 3 and 4, or 5 and 2, or 6 and 1. Understanding number bonds is essential preparation for addition and subtraction, and forms the basis of mental computation strategies.

Estimation

Estimation is the ability to make a reasonable guess about a quantity without counting. Even young children can develop estimation skills by comparing unknown quantities to known benchmarks (e.g., "Is it closer to 5 or closer to 20?").

The Australian Curriculum v9 for Mathematics develops number sense progressively through the Number strand. Here is what students are expected to learn at each level in the early primary years.

Foundation

• Name, represent, and order numbers to at least 20, including zero
• Subitise small collections of objects
• Connect number names, numerals, and quantities up to 10, and beyond
• Represent practical situations involving addition and sharing
• Follow and create simple patterns

At the Foundation level, the emphasis is on building a rich, connected understanding of numbers through hands-on exploration, play, and daily routines. Students are not expected to perform formal operations — instead, they develop the intuitive understanding that underpins all later work.

Year 1

• Count to and from at least 120, recognising the pattern of the number system
• Represent and solve simple addition and subtraction problems using a range of strategies
• Partition numbers using place value (tens and ones)
• Skip count by twos, fives, and tens
• Recognise, continue, and create number patterns

Year 1 marks a significant step up. Students move from exploring numbers to operating with them. A strong number sense foundation makes this transition much smoother — children who understand number bonds, for example, find addition and subtraction far more intuitive.

Year 2

• Recognise, represent, and order numbers to at least 1000
• Group, partition, and rearrange collections up to 1000 using hundreds, tens, and ones
• Solve addition and subtraction problems involving two-digit numbers
• Skip count by twos, threes, fives, and tens from any starting point
• Recall and demonstrate proficiency with addition facts to 20

By Year 2, students with strong number sense can reason flexibly about numbers. They understand that 47 is 40 + 7, or 30 + 17, or close to 50 — and they use this understanding to solve problems mentally rather than relying solely on counting or memorised procedures.

The best number sense activities are hands-on, visual, and connected to children's real experiences. Here are ten practical activities that build strong number sense in Foundation to Year 2 classrooms.

1. Subitising Flash Cards and Dot Plates

Show students cards or paper plates with dot arrangements for 1–2 seconds, then hide them. Students say how many dots they saw without counting. Start with quantities to 5, then extend to 10 using familiar patterns (dice arrangements, domino patterns, ten frame configurations). Regular, brief subitising practice — even just five minutes a day — builds powerful number visualisation skills.

2. Ten Frame Activities

Ten frames are one of the most versatile tools for early number sense. Students place counters on a ten frame to represent numbers, see how numbers relate to 5 and 10, explore addition by filling frames, and visualise subtraction by removing counters. Provide both five frames (for Foundation) and ten frames (for Year 1 and 2), and use double ten frames to extend to numbers beyond 10.

3. Number Lines (Floor-Sized and Desk-Sized)

Create a large number line on the classroom floor using tape and number cards, and give students individual desk-sized number lines. Use them for counting forwards and backwards, finding numbers that come before and after, comparing numbers, and later for addition and subtraction by "jumping" along the line. Floor number lines are especially powerful because children can physically walk the number sequence.

4. Counting Collections

Gather collections of interesting objects — shells, buttons, bottle caps, natural materials, small toys — and have students count them. This deceptively simple activity builds one-to-one correspondence, cardinality, and grouping skills. Encourage students to organise their collections into groups (by twos, fives, or tens) to count more efficiently, and to record their count using drawings and numerals.

5. Numeral Formation (Sand Trays, Playdough, Sky Writing)

Learning to write numerals correctly is part of number recognition. Multi-sensory approaches work best: tracing numerals in sand trays, forming them from playdough, writing them large in the air ("sky writing"), and tracing over textured numeral cards. Always connect the written numeral to the quantity it represents — form the numeral 5, then show 5 objects.

6. Part-Part-Whole Mats

Give students a mat divided into three sections (two "parts" and one "whole"). Students use counters to explore how a number can be split into different parts. For example, 8 can be 4 and 4, or 5 and 3, or 6 and 2. This builds the number bond understanding that directly supports addition and subtraction.

7. Domino Matching and Sorting

Dominoes are excellent for subitising and number bonds. Students can match domino ends with the same quantity, find dominoes that total a target number, sort dominoes by their total, or use them to practise addition. The dot patterns on dominoes naturally encourage subitising rather than one-by-one counting.

8. Number of the Day Routine

Choose a "number of the day" and explore it as a class. How many ways can we show this number? Represent it with counters, on a ten frame, on a number line, as a domino pattern, as a tally, in words, and as an equation. This daily routine builds flexible thinking about numbers and connects different representations.

9. Rekenrek (Arithmetic Rack) Activities

A rekenrek is a counting frame with rows of 10 beads (5 red and 5 white). The colour change at 5 makes it a powerful tool for subitising, seeing numbers in relation to 5 and 10, and developing mental strategies for addition and subtraction. Use a class-sized rekenrek for whole-group work and individual ones for student practice.

10. Estimation Jars

Fill a clear jar with a countable quantity of objects and ask students to estimate how many are inside. Provide a "benchmark" — a smaller jar with a known quantity — so students have a reference point. After estimating, count together to check. Change the jar contents regularly to build estimation skills across different quantities and object sizes.

You don't need special resources or a teaching degree to build your child's number sense at home. Number sense develops naturally when children notice, talk about, and play with numbers in everyday life. Here are some simple ways to weave number sense into your daily routine.

Cooking and Baking

Cooking is full of maths. Count the eggs, measure the cups of flour, set the timer, divide the mixture between muffin tins. Talk about quantities as you go: "We need three eggs. We've cracked one — how many more do we need?"

Shopping

The supermarket is a classroom in disguise. Ask your child to count items into the basket, compare prices ("Which costs more?"), estimate how many apples are in the bag, or help you find the right aisle number.

Games

Board games, dice games, and card games build number sense without feeling like work. Games that involve counting spaces, comparing numbers, adding dice totals, or collecting sets of objects are particularly valuable. Snakes and ladders, Uno, dominoes, and simple dice addition games are all excellent choices.

Counting Everyday Objects

Count anything and everything — stairs, cars in the car park, birds at the park, grapes on the plate. For younger children, focus on small quantities and one-to-one correspondence. For older children, practise skip counting, estimating, and grouping.

Noticing Numbers in the Environment

Point out numbers wherever you see them — letterboxes, speed signs, clocks, price tags, bus numbers, sports scores. Ask questions: "What number is that? What comes after it? Is that a big number or a small number?"

Using TeachBuySell Resources at Home

If you'd like structured activities to use at home, search for number sense resources on TeachBuySell. Many resources are designed to be parent-friendly, with clear instructions and materials that are easy to prepare. Look for games, flash cards, and printable activities that make number practice feel like play.

For related resources, see our Addition & Subtraction Activities page for the next step in your child's maths journey, or browse Place Value Activities and Primary Maths Worksheets for a broader range of maths resources.