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.

• Year 2
• Mathematics
• 4 activities
• 15 min–45 min

Learning Objectives

1. Compare the efficiency of 'doubles', 'near doubles', and 'making to ten' strategies for solving addition problems.
2. Explain the process of 'making to ten' to bridge a number to the nearest multiple of ten.
3. Calculate sums using 'doubles' and 'near doubles' strategies.
4. Apply the 'making to ten' strategy to solve addition facts involving numbers that do not immediately sum to ten.
5. Justify the selection of a specific mental math strategy for a given addition problem.

Academic Speed Dating

⏱ 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.

Prepare & details

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.

Setup: Two rows of chairs facing each other

Materials: Discussion prompt cards (one per round), Timer or bell

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

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.

Prepare & details

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.

Setup: Tables/desks arranged in 4-6 distinct stations around room

Materials: Station instruction cards, Different materials per station, Rotation timer

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

Academic Speed Dating

⏱ 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.

Prepare & details

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.

Setup: Two rows of chairs facing each other

Materials: Discussion prompt cards (one per round), Timer or bell

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

Academic Speed Dating

⏱ 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.

Prepare & details

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.

Setup: Two rows of chairs facing each other

Materials: Discussion prompt cards (one per round), Timer or bell

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

Teaching This Topic

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.

What to Expect

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.

Watch Out for These Misconceptions

Common Misconception

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

What to Teach Instead

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.

Common Misconception

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

What to Teach Instead

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.

Common Misconception

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

What to Teach Instead

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.

Assessment Ideas

Quick Check

After Partner Strategy Duels, give students a half-sheet with four problems (e.g., 7+7, 6+7, 15+6, 12+9). Ask them to write the strategy they used and the answer for each problem.

Discussion Prompt

During Whole Class Number Talks, pose the problem 9+4 and ask two volunteers to share their strategies. Follow up with: 'Which strategy felt faster and why?' Guide the class to name the strategy used and its efficiency.

Exit Ticket

After Strategy Hunts, give each student a card with 12+5 and ask them to write two different mental strategies, circle the most efficient, and explain why in one sentence.

Extensions & Scaffolding

• Challenge students who finish early to create their own near-double problem using odd numbers and explain the adjustment step to a partner.
• Scaffolding: Provide counters or ten-frame cards at the Making to Ten station for students to visualize the split before calculating.
• Deeper exploration: Students research and present another mental math strategy, like compensation, and compare its efficiency to doubles or making to ten.

Key Vocabulary

Doubles	Adding a number to itself, such as 7 + 7. This strategy uses known facts to solve similar problems.
Near Doubles	Using a known doubles fact to solve a problem where the addends are close, like 7 + 8, by thinking of it as 7 + 7 + 1.
Making to Ten	A strategy where one addend is broken apart to complete a ten with the other addend, for example, 8 + 5 becomes 8 + 2 + 3, which equals 10 + 3.
Partitioning	Breaking a number into smaller parts to make calculations easier, such as breaking 6 into 2 and 4 to help make a ten.