ACARA v9 CONTENT DESCRIPTION “recognise, represent and order numbers to at least 120 using physical and virtual materials, numerals, number lines and charts”
In Foundation, numbers ran to twenty. In Year 1 they stretch much further — to one hundred and twenty — and the surprise for a child is that nothing really changes. The counting keeps the same steady beat. After ninety-nine comes one hundred, then one hundred and one, and on it goes, the same rhythm of ones rolling over into the next ten. This unit is about seeing that the number system simply keeps going, and learning two new pictures that make the larger numbers easy to read.
Counting Past 100
After 99 comes 100, then 101, 102 — the counting does not stop or change. It keeps the same steady pattern past one hundred.
98 to 102
One hundred is a milestone, not a wall
The first big idea is that counting does not stop at 100. One hundred is a milestone, not a wall. A child who can count to twenty already knows the pattern; they just need to trust it past the hundred mark. Saying the numbers aloud from ninety up to a hundred and ten, and hearing how “one hundred and one, one hundred and two” echoes “one, two”, is what makes the pattern click.
On the Number Line
A number line shows where a number sits and how far it is from others. Slide to place a number between 0 and 120.
75 is in the second half of 0 to 120.
A line shows order and distance
The second idea is the number line. A number line lays the numbers out in a straight row, in order, evenly spaced. It does two jobs at once: it shows which number is bigger (further along the line) and it shows how far apart numbers are. Placing a number on a line to 120 helps a child feel that 110 sits near the far end, while 30 sits close to the start — order and distance, seen at a glance.
The Hundred Chart
Ten in each row. Numbers in the same column end in the same digit — tap a number to see its column light up. The pattern goes all the way to 120.
34 ends in 4 — like every number in its column.
The chart makes the pattern visible
The third idea is the hundred chart — here stretched to 120. Laid out in rows of ten, it turns counting into a grid full of patterns. Moving right adds one; moving straight down adds ten. Every number in a column ends in the same digit. These patterns are not decoration; they are the structure of our number system made visible, and spotting them is how a child begins to predict and reason rather than count one by one.
Put Them in Order
Order means smallest to largest. Tap the numbers from least to greatest — remember 109 is bigger than 96.
Keep going, smallest first.
Smallest to largest
Finally, all of this supports ordering — arranging numbers from smallest to largest. Once a child can place numbers on a line and read them on a chart, comparing becomes natural: 109 is more than 96, even though 96 “feels” long, because 109 has an extra hundred. Ordering numbers to 120 is where recognising, representing and comparing all come together.
Tens and Ones
Big numbers are bundles of ten plus some ones. Build a number with bundles (tens) and loose counters (ones).
7 tens and 4 ones make 74.
Tens and ones underneath it all
Underneath both pictures is place value: the idea that a two- or three-digit number is built from tens and ones. Forty-six is four tens and six ones; one hundred and twenty is twelve tens. Bundling ten ones into a single ten, and seeing a number as bundles plus leftovers, is the foundation everything else in Year 1 number will stand on. The hundred chart and the number line are just two ways of showing this same tens-and-ones structure.
Five windows, one idea
The five visualisations below build this picture step by step: count straight past one hundred, place a number on a line to 120, explore the patterns in a hundred-and-twenty chart, put numbers in order, and build numbers from tens and ones. Each one is a different window onto the same idea — the numbers keep going, in a pattern we can see.
Quick self-check
1. What number comes right after 99?
2. On a hundred chart, numbers in the same column...
3. Which is the largest?
4. 7 tens and 4 ones make...
5. On a number line from 0 to 120, the number 110 is...