Mathematics · Foundation · Counting Objects to 10 · Term 1

One More, One Less

Students identify equivalent fractions and compare and order fractions with different denominators.

• ACARA Content Descriptions
• AC9M6N03

About This Topic

One more, one less introduces Foundation students to forward and backward counting within 0 to 10. They explore how adding or removing a single object changes the total, using familiar contexts like books on a shelf or blocks in a tower. Key questions guide practice: if 8 books plus one more, how many now? Show one less than 10 with counters. What comes after 6 or before 7? These build fluency in number sequences and early addition, subtraction concepts.

This topic supports Australian Curriculum outcomes for counting reliably, recognising numerals, and solving simple problems with concrete materials. Students connect oral counting to written symbols and develop one-to-one correspondence. It lays groundwork for partitioning numbers and understanding teen numbers later.

Active learning excels here through manipulatives and movement. When students physically add or remove items, hop on floor number lines, or play counting games with partners, they experience number relationships kinesthetically. This approach boosts engagement, corrects errors in real time, and makes abstract ideas concrete and joyful.

Key Questions

1. If there are 8 books on the shelf and we add one more, how many are there?
2. Can you show me one less than 10 using your blocks?
3. What number is one more than 6? What number is one less?

Learning Objectives

• Demonstrate counting one more or one less than a given number of objects up to 10.
• Identify the numeral that represents one more or one less than a given quantity.
• Compare quantities to determine which is one more or one less.
• Apply the concept of 'one more' and 'one less' to solve simple word problems involving objects up to 10.

Before You Start

Counting Objects to 5

Why: Students need to be able to count a small set of objects accurately before extending this to numbers up to 10.

Number Recognition to 5

Why: Recognizing numerals up to 5 is necessary to connect the quantity of objects to their symbolic representation.

Key Vocabulary

One more	The quantity that results from adding a single object to a group. It is the next number in a counting sequence.
One less	The quantity that remains after removing a single object from a group. It is the previous number in a counting sequence.
Count on	To continue counting from a given number, typically to find 'one more'.
Count back	To count in reverse order from a given number, typically to find 'one less'.

Watch Out for These Misconceptions

Common Misconception

One less than 1 is nothing, so they skip to 10 or say 'gone'.

What to Teach Instead

Use zero as a concrete starting point with empty hands or bowls. Active demos like removing the last counter from 1 show it becomes 0. Group discussions reveal peers' strategies, building consensus on sequences including zero.

Common Misconception

Adding one more to 9 jumps to 11, skipping 10.

What to Teach Instead

Floor number lines let students physically step from 9 to 10. Hands-on counting objects reinforces steady progression. Partner games provide immediate feedback, helping students internalise the pattern through repetition.

Common Misconception

One more always means the biggest number possible.

What to Teach Instead

Compare multiple examples with visuals like bead strings. Small group sorting activities distinguish relative changes. Movement games clarify that 'one more' shifts position predictably, not absolutely.

Active Learning Ideas

Partner Relay: More or Less Toss

Pairs face each other with 10 counters each. One student says a number from 0-9; partner tosses one counter into a bowl for 'one more' or removes one for 'one less,' then counts aloud to confirm. Switch roles after 5 turns. Record final scores on a class chart.

25 min·Pairs

Whole Class: Number Line March

Create a giant floor number line 0-10 with tape and cards. Teacher calls 'one more than 5' or 'one less than 8'; whole class moves to positions, using claps or jumps to count. Discuss positions as a group before next call.

30 min·Whole Class

Small Groups: Block Tower Challenge

Groups of 3-4 build towers to match numbers 0-10, then add or remove one block as directed by cards (e.g., 'one more than 7'). Count and compare towers, noting changes. Photograph for a class display.

35 min·Small Groups

Individual: Finger Counting Cards

Students draw cards with numbers 0-9, show one more or less on fingers, then draw or stamp the new amount. Complete 10 cards, self-check with a number line strip.

20 min·Individual

Real-World Connections

• When a child is setting the table for dinner and needs to add one more plate because an unexpected guest arrives, they are using the 'one more' concept.
• A shopkeeper might count the number of apples in a basket and then remove one to sell, demonstrating 'one less' in a transaction.
• During a game of 'musical chairs', students observe that when one chair is removed, there is 'one less' chair than the number of players.

Assessment Ideas

Quick Check

Present a small collection of 5-7 counters. Ask the student: 'If I add one more counter, how many will there be?' Then, remove one counter and ask: 'Now how many are there? Can you show me one less?'

Discussion Prompt

Hold up a card with a numeral (e.g., 7). Ask: 'What number is one more than 7?' Then ask: 'What number is one less than 7?' Encourage students to use their fingers or draw a picture to explain their answer.

Exit Ticket

Give each student a small card with a picture of 4 objects. Ask them to draw one more object and write the total number of objects. On the back, ask them to draw one less object and write the new total.

Frequently Asked Questions

What are effective activities for one more one less in Foundation Maths?

Partner relays with counters, floor number line marches, block tower builds, and finger counting cards work well. Each involves concrete manipulatives and movement to represent changes. These keep students engaged for 20-35 minutes, fostering collaboration and immediate feedback on counting accuracy.

How does active learning benefit teaching one more and one less?

Active learning uses manipulatives, games, and body movement to make number changes tangible. Students physically add or remove items, hop to positions, or build towers, embedding sequences kinesthetically. This reduces counting errors, builds confidence through play, and connects abstract ideas to real actions, outperforming worksheets alone.

Common misconceptions in one more one less for Foundation students?

Students may skip 10 after 9, treat zero as nonexistent, or confuse relative changes with absolute size. Concrete demos correct these: show sequences with objects, include zero explicitly, and compare examples visually. Peer discussions in groups help refine understanding.

How to align one more one less with Australian Curriculum Foundation?

Link to ACMNA001 and ACMNA002 by using concrete materials for counting sequences and simple addition/subtraction. Pose key questions in context, like shelf books or block towers. Track progress with observations of reliable counting to 10 and numeral recognition.