ACARA v9 CONTENT DESCRIPTION “quantify sets of objects, to at least 120, by partitioning collections into equal groups using number knowledge and skip counting”
Tip a box of pencils onto the mat and ask a Year 1 class how many there are. Most children will start the same way: one, two, three… Somewhere around fourteen, a hand slips, two pencils get counted twice, and the answer comes out different for every child. Counting by ones works, but for bigger collections it is slow and fragile. This unit is about the stronger tool: make equal groups, then skip count the groups. Five pencils, ten pencils, fifteen — three moves instead of fifteen. The Australian Curriculum asks Year 1 students to quantify collections to at least 120 this way, and once children feel why groups win, the rest of the year’s number work gets easier.
The pile of pencils
Seventeen pencils on the mat. Count them by ones, then count them in fives.
Click each pencil to count it by ones.
Equal groups, fewer moves
In the first visualisation you can feel the difference in your fingertips. Counting the scattered pile means tracking every single pencil with your eyes — lose your place once and you have to start again. Group the same pencils into fives and the job shrinks to five quick moves. Nothing about the collection changed; only the way we organised it did. That is the heart of this descriptor: a total is found faster, and more reliably, when the collection is partitioned into equal groups first.
Hop along the line
Every hop lands one whole group further along. Choose a group size and hop.
Press Hop to start counting by 2s.
Skip counting names whole groups
Skip counting can sound like a chant, but each number in the chant is doing real work: it names the running total after one more whole group joins the count. Hop along the line by twos and every landing point is two more than the last. By fives, every landing is five more. The chant and the line say the same thing — skip counting is just counting, done a group at a time. Twos, fives and tens are the patterns Year 1 children practise most, because they match pairs, hands and our place-value system.
Twelve, four ways
The same 12 counters, grouped four different ways. The total never changes.
12 counters in groups of 3. Count them one group at a time.
Same collection, different groups
A collection does not care how we group it. Twelve counters can be six pairs, four threes, three fours or two sixes, and every arrangement still lands on twelve. Watching the same dozen rearrange itself builds an idea mathematicians call conservation of number: grouping changes the counting, never the quantity. It also plants an early seed for multiplication — though in Year 1 the goal is simply confident, flexible counting.
Bundle to 120
Craft sticks in bundles of ten. Count the tens, then switch to ones.
10, 20, 30. Counted by tens — 3 moves.
Tens are the favourite group
Among all the group sizes, ten is special, because our whole number system is built on it. Bundle craft sticks into tens and the count becomes 10, 20, 30… — and when a few loose sticks remain, children switch smoothly to ones: 40, then 41, 42, 43. That switch is exactly the tens-and-ones thinking from the previous unit, now used as a counting strategy. Push on to twelve bundles and you reach 120, the Year 1 landmark: a number that feels enormous counted by ones, and entirely manageable counted by tens.
The egg carton count
A carton holds a dozen eggs in two rows of six. Perfect for counting by twos.
Two rows of six. Count the eggs a pair at a time.
Groups in the kitchen
Equal groups are hiding all over an Australian home. The clearest example sits in the fridge: an egg carton holds a dozen eggs in two tidy rows of six, which makes it perfect for counting by twos. Cartons, six-packs, pairs of socks on the line — children who spot the groups around them get free counting practice every single day.
Quick self-check
1. Count by fives: 5, 10, 15 ... What comes next?
2. There are 4 bags with 10 apples in each bag. How many apples altogether?
3. Which list counts a dozen eggs by twos?
4. You have 6 bags of 5 oranges. What is the quickest reliable way to find the total?
5. A class collects 12 bundles of ten sticks. How many sticks?