Mathematics · Year 2

Active learning ideas

Mental Math Strategies for Addition

Students in Year 2 learn mental math strategies best when they practice in active, social settings. These methods—like doubles, near doubles, and making to ten—become automatic when students explain their thinking aloud, compare approaches, and see the speed of efficient strategies over counting one-by-one.

• ACARA Content Descriptions
• AC9M2N03

• 15–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 30 min · Pairs

Partner Strategy Duels: Addition Showdown

Pairs draw cards with sums like 9+6 and race to solve using different strategies, then explain their choice to partners. Switch roles after each round and record the fastest method. Debrief as a class on patterns.

Compare the efficiency of different mental math strategies for a given addition problem.

Facilitation Tip

During Partner Strategy Duels, remind students to record the time taken for each method to highlight the speed advantage of efficient strategies.

What to look for

Present students with a list of addition problems (e.g., 7+7, 6+7, 8+5, 9+4). Ask them to write the strategy they used for each problem and the answer. For example, for 8+5, they might write 'making to ten' and 13.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 02

• Stations Rotation
• 45 min · Small Groups

Stations Rotation: Strategy Workshops

Set up stations for doubles (domino matching), near doubles (dice rolls adjusted by 1), making to ten (ten-frame cards), and mixed practice (whiteboard challenges). Groups rotate every 7 minutes, noting strategy use in journals.

Justify why 'making to ten' is a powerful mental strategy.

Facilitation Tip

In Strategy Workshops, circulate and ask students to explain their chosen strategy aloud before moving to the next station.

What to look for

Pose the problem: 'Sarah solved 9 + 4 by thinking 9 + 1 + 3. Ben solved it by thinking 10 + 4 - 1. Who used 'making to ten' and why is that strategy helpful?' Facilitate a class discussion comparing their approaches.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 03

• Stations Rotation
• 20 min · Whole Class

Whole Class Number Talks: Strategy Shares

Pose problems like 14+7 on the board. Students signal thinking with fingers (1 for doubles, 2 for near doubles, 3 for making to ten), then share and justify aloud. Tally most efficient strategies on a chart.

Predict which mental strategy would be most suitable for various addition facts.

Facilitation Tip

For Strategy Shares, select students to present solutions that use doubles, near doubles, and making to ten to model flexibility.

What to look for

Give each student a card with an addition problem, such as 12 + 5. Ask them to write down two different mental strategies they could use to solve it and state which strategy they think is most efficient and why.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 04

• Stations Rotation
• 15 min · Individual

Individual Strategy Hunts: Fact Families

Students get fact family sheets (e.g., around 10+5) and circle numbers to make tens, draw doubles, or note near doubles. They solve 10 problems and pick their top strategy for each.

Compare the efficiency of different mental math strategies for a given addition problem.

Facilitation Tip

In Strategy Hunts, provide blank fact family charts so students can record multiple expressions for the same sum.

What to look for

Present students with a list of addition problems (e.g., 7+7, 6+7, 8+5, 9+4). Ask them to write the strategy they used for each problem and the answer. For example, for 8+5, they might write 'making to ten' and 13.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

A few notes on teaching this unit

Teach this topic by modeling think-alouds during whole-class problems so students hear how experts decide which strategy to use. Rotate practice formats daily to keep engagement high and prevent reliance on a single method. Avoid teaching strategies in isolation; always connect them to the same set of facts so students see how flexibility speeds up fluency.

Students will show fluency by choosing efficient strategies without counting all or using fingers. They will explain their choices, compare methods with peers, and demonstrate accuracy across addition facts to at least 100 using mental math only.

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Watch Out for These Misconceptions

• During Partner Strategy Duels, watch for students who always count on from the larger number even when it slows their speed.

  Provide a visible timer and have partners record the seconds taken for each method. Ask them to explain which strategy felt faster and why, guiding them to notice the efficiency of making to ten or near doubles.

• During Strategy Workshops, watch for students who believe doubles only work with even addends and avoid odd numbers entirely.

  Include cards with odd doubles like 7+7 in the doubles deck and provide sentence stems: 'This is a double because ____, and to adjust for near doubles, I ____.' Circulate to prompt these reflections during play.

• During Strategy Hunts, watch for students who limit making to ten to numbers close to ten, such as 9+1 or 8+2.

  Include problems like 13+8 in the station cards and ask students to verbalize the split: 'I split 13 into 10 and 3, then add 8 to 10 first.' Provide example cards to model this language.

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Methods used in this brief

• Stations Rotation