Picture this: your child is in a shop, working out change. Or sitting in a maths test, racing through multiplication. Or helping you split a pizza equally. In every one of these moments, mental maths is the skill that makes the difference.
Mental maths isn’t just about being “good at numbers.” It’s about building speed, confidence, and independence — the kind that sticks for life.
If your child plays Hit the Button, you already know how powerful quick-fire maths practice can be. That game — and the tricks in this article — work together to rewire how children think about numbers.
In this guide, you’ll discover 10 mental maths tricks every child at KS1 and KS2 should know. Each one comes with a clear explanation, a real example, and a mini exercise your child can try straight away.
Whether you’re a parent looking to support learning at home, or a teacher building number fluency in the classroom — you’re in the right place.
Let’s get started.
What Is Mental Maths?
Mental maths simply means doing calculations in your head — no calculator, no written working out.
But it’s more than just memorising facts. It’s about using smart strategies to reach the right answer quickly and confidently.
For example:
Rather than counting 47 + 9 on fingers, a child with strong mental maths skills thinks: “47 + 10 = 57, minus 1 = 56.” Done in seconds.
These strategies become automatic with practice — just like reading becomes automatic once you know your phonics.
Why Mental Maths Matters (KS1, KS2, and Beyond)
Mental maths is a core part of the UK National Curriculum at both KS1 and KS2. Children are expected to:
- Recall number bonds to 10 and 20 (KS1)
- Know all times tables up to 12 × 12 by Year 4 (KS2)
- Apply mental strategies to addition, subtraction, multiplication, and division
But the benefits go far beyond school tests.
Cognitive benefits include:
- Stronger working memory
- Faster processing speed
- Greater confidence in problem-solving
- Better concentration across all subjects
Research in mathematics education consistently shows that children who develop early number fluency perform better in secondary school maths — and even in science and technology subjects.
Mental maths also reduces maths anxiety. When a child knows they can find the answer, they stop fearing the question.
The 10 Mental Maths Tricks Every Child Should Learn
Trick 1: Adding 9 (or 19, 29…) the Smart Way
Explanation: Instead of adding 9 directly, add 10 and subtract 1. It’s much easier for the brain to handle.
Example: 34 + 9 → Think: 34 + 10 = 44, then 44 − 1 = 43
Mini tip: This works for 19 too. Add 20, subtract 1. For 29, add 30, subtract 1.
Trick 2: Number Bonds to 10 and 20
Explanation: Number bonds are pairs of numbers that add up to a target number. Knowing them instantly is like having a secret code.
Bonds to 10: 1+9, 2+8, 3+7, 4+6, 5+5 Bonds to 20: 12+8, 15+5, 17+3, 11+9
Example: 6 + ? = 10 → The answer is 4, no working needed.
Mini tip: Once your child knows bonds to 10, bonds to 100 become easy. 30 + 70 = 100. Same pattern.
Trick 3: Doubling and Halving
Explanation: Doubling (×2) and halving (÷2) are often the fastest routes to an answer — especially for multiplication.
Example: 14 × 4 → Double 14 = 28, double again = 56 Or: 36 ÷ 4 → Half of 36 = 18, half again = 9
Mini tip: Teach children to spot even numbers first. If both numbers are even, halving and doubling is almost always faster.
Trick 4: The Compensation Method
Explanation: Round one number to a “friendly” number (usually ending in 0), do the easy sum, then adjust.
Example: 53 + 38 → Round 38 to 40: 53 + 40 = 93, then subtract 2 = 91
Mini tip: This works brilliantly for subtraction too. 72 − 29 → 72 − 30 = 42, add 1 = 43
Trick 5: Multiplying by 10, 100, and 1000
Explanation: Children often learn “add a zero” — but that’s misleading with decimals. The correct understanding is: digits move left one place for ×10, two places for ×100.
Example: 6 × 10 = 60 (digit moves one place left) 6 × 100 = 600 (moves two places left)
Mini tip: Use a place value chart to show this visually. It prevents confusion with decimals later.
Trick 6: Times Tables Patterns
Explanation: Every times table has patterns that make it easier to remember. Children who spot these patterns learn their tables far faster than those who just chant.
Key patterns:
| Table | Pattern |
|---|---|
| ×2 | Always even |
| ×5 | Ends in 0 or 5 |
| ×9 | Digits always add to 9 (e.g. 27: 2+7=9) |
| ×10 | Always ends in 0 |
| ×11 | Up to 9×11: digits repeat (33, 44, 55…) |
Example: Can’t remember 9 × 7? Use the finger trick: hold up 10 fingers, fold down the 7th finger. You see 6 fingers on the left and 3 on the right. Answer: 63.
Mini tip: Hit the Button maths game is one of the best tools for making these patterns automatic. The timed format builds genuine recall — not just slow counting.
Trick 7: Splitting Numbers (Partitioning)
Explanation: Break a number into its tens and units, work with each part separately, then combine.
Example: 43 + 35 → (40 + 30) + (3 + 5) = 70 + 8 = 78
Or for multiplication: 6 × 14 → 6 × 10 = 60, 6 × 4 = 24, total = 84
Mini tip: This is especially helpful for children who find mental maths overwhelming. Breaking numbers down makes them feel manageable.
Trick 8: Using Known Facts to Find Unknown Ones
Explanation: If a child knows 6 × 6 = 36, they can quickly work out 6 × 7 by adding one more group of 6.
Example: 6 × 7 = 6 × 6 + 6 = 36 + 6 = 42
Or: Know 8 × 8 = 64? Then 8 × 9 = 64 + 8 = 72
Mini tip: Encourage children to start from their strongest known facts and build outward. Confidence grows this way.
Trick 9: Subtraction by Adding On (Shopkeeper’s Method)
Explanation: Instead of subtracting directly, count up from the smaller number to the larger. This is the same method used to calculate change.
Example: 83 − 47 → Start at 47, add 3 = 50, add 33 = 83. Total added = 36
Mini tip: This works brilliantly for children who struggle with column subtraction mentally. Counting up feels natural and avoids borrowing confusion.
Trick 10: Multiplying by 4 and 8 Using Doubling
Explanation: ×4 = double, then double again. ×8 = double three times.
Example: 13 × 4 → 13 × 2 = 26, 26 × 2 = 52 13 × 8 → 26 × 2 = 52, 52 × 2 = 104
Mini tip: Once children see that ×4 and ×8 are just repeated doubling, these tables stop feeling scary.
Common Mistakes Children Make (And How to Fix Them)
These mistakes come up again and again in classrooms. Knowing them helps you fix them quickly.
1. Counting on fingers for every calculation Why it happens: No strategy was taught. Fix: Teach number bonds and doubling first — these are the fastest replacements.
2. Forgetting to adjust after rounding Why it happens: They remember to round but forget the compensation step. Fix: Always write “adjust!” as a reminder until it becomes automatic.
3. Saying “add a zero” for ×10 Why it happens: It’s a shortcut that breaks down with decimals. Fix: Teach place value movement from the start. Use a chart.
4. Mixing up ×6 and ×7 tables Why it happens: These share no obvious pattern and sit in the hardest zone. Fix: Use 6 × 7 = 42 as a standalone “anchor fact.” Practise it daily on Hit the Button.
5. Rushing and making careless errors Why it happens: Speed is prioritised over accuracy. Fix: Slow down first, build accuracy, then build speed. The game rewards both.
6. Avoiding subtraction mentally Why it happens: Subtraction feels harder than addition. Fix: Teach the “add on” method. Most subtractions become additions in disguise.
7. Not checking if the answer is reasonable Why it happens: Children just want to move on. Fix: Build the habit of asking “does this make sense?” after every answer.
Fun Practice Methods That Actually Work
At home:
- Kitchen maths: Ask questions while cooking. “We need 3 bags of rice, each weighs 500g. How much is that altogether?”
- Car journeys: Call out a times table question at every red light.
- Score tracking: Let your child keep score in a family board game and calculate the totals mentally.
In the classroom:
- Daily starter: 5 quick-fire mental maths questions to begin each lesson.
- Whiteboard races: Children write answers on mini whiteboards — no pressure, just speed.
- Peer quizzing: Pairs take turns asking each other times table questions.
Real-life applications:
- Working out if they have enough pocket money
- Calculating how long until a favourite programme starts
- Doubling a recipe when baking
Practise These Tricks With Hit the Button
One of the most effective ways to build mental maths speed is through Hit the Button — an interactive maths game designed specifically for KS1 and KS2 children.
Here’s why it works so well:
Speed: The timed format forces children to recall facts rather than work them out slowly. Over time, this creates genuine fluency.
Accuracy: Instant feedback means children don’t practise mistakes. They correct in real time.
Confidence: Starting on easier levels and progressing gives children a sense of achievement. That feeling is powerful.
Hit the Button covers number bonds, times tables, doubling, halving, and division facts — every skill mentioned in this article. It’s not just a game. It’s a targeted maths workout.
The Hit the Button times tables mode is particularly effective for Year 3 and Year 4 children preparing for the Multiplication Tables Check (MTC). Regular short sessions — even 5–10 minutes a day — produce noticeable results within weeks.
Try it yourself. Set a target: can your child beat their own score three days in a row?
Practice Questions
Try these mental maths questions using the tricks above. Answers are at the bottom.
Addition & Subtraction:
- 56 + 9 = ?
- 83 − 28 = ?
- 47 + 38 = ?
- 100 − 64 = ?
Multiplication & Division: 5. 7 × 6 = ? 6. 9 × 8 = ? 7. 48 ÷ 4 = ? 8. 13 × 4 = ?
Mixed: 9. Double 37 = ? 10. Half of 96 = ? 11. 25 × 4 = ? 12. 6 × 7 + 5 = ?
Answers: 1) 65 | 2) 55 | 3) 85 | 4) 36 | 5) 42 | 6) 72 | 7) 12 | 8) 52 | 9) 74 | 10) 48 | 11) 100 | 12) 47
Expert Tips for Parents and Teachers
For parents:
- Little and often beats long sessions. Ten minutes daily is more effective than an hour at the weekend. The brain retains better with spaced repetition.
- Celebrate process, not just answers. If your child explains their thinking, praise that — even if the answer is wrong.
- Use the language of maths. Say “how did you work that out?” regularly. This builds metacognition (thinking about thinking).
- Don’t rescue too quickly. Give children 10–15 seconds to think before jumping in. Productive struggle leads to deeper learning.
For teachers:
- Target the “tricky six”: 6×7, 6×8, 7×8, 7×9, 8×9, 6×9 account for the majority of times table errors. Prioritise these.
- Mix retrieval methods: Chanting, writing, games, and oral quizzing each activate different memory pathways. Use all of them.
- Use Hit the Button as a starter activity: Even 5 minutes at the start of a lesson measurably improves arithmetic fluency over a half-term.
- Track progress visibly: Children respond well to seeing their speed improve on a chart. Make progress concrete.
Advanced Insight: Why These Tricks Work (The Learning Psychology Behind It)
Most articles just list tricks. Here’s why they actually work — and why that matters for how you teach them.
The human brain has two systems for solving maths problems:
System 1 — Fast, automatic, instinctive. This is where known facts live: “7 × 8 = 56” recalled instantly.
System 2 — Slow, deliberate, effortful. This is where we work things out step by step.
Children who rely on System 2 for every maths question quickly become overwhelmed — especially in timed conditions. The goal of mental maths practice is to move facts from System 2 into System 1.
This happens through retrieval practice — actively recalling facts, not just reviewing them. Games like Hit the Button are retrieval practice by design. Every time a child presses the right answer under time pressure, they strengthen the neural pathway for that fact.
Research from cognitive science (including work by Robert Bjork on “desirable difficulties”) shows that slightly effortful recall — where the child has to try to remember — produces stronger long-term memory than easy, passive review.
That’s why the tricks in this article aren’t shortcuts. They’re structured pathways that train the brain to find the efficient route — until that route becomes automatic.
Frequently Asked Questions
What is Hit the Button and how does it help with mental maths? Hit the Button is an interactive online maths game for KS1 and KS2 children. It covers number bonds, times tables, halving, doubling, and division in a timed format. The game builds speed and accuracy through repeated retrieval practice — one of the most effective methods in mathematics education.
At what age should children start learning mental maths tricks? Children can begin with simple number bond tricks as early as age 5–6 (Year 1). More complex strategies like compensation and partitioning are typically introduced in Years 3–4. Most children can access all 10 tricks in this article by Year 5.
How long does it take to improve at mental maths? With consistent daily practice of 10–15 minutes, most children show measurable improvement within 4–6 weeks. The key is regularity — short, daily practice is far more effective than occasional long sessions.
What are the most important mental maths facts to learn first? Start with: number bonds to 10, doubling numbers to 20, then the 2, 5, and 10 times tables. Once these are automatic, build outward to 3, 4, 6, 8, and 9 times tables.
Why does my child struggle with the 7 and 8 times tables? These tables have no easy visual pattern and few “hooks” for memory. They require targeted, repeated practice. Focus on specific facts (like 7×8=56) rather than chanting the whole table. Games like Hit the Button times tables mode are particularly effective here.
Can mental maths tricks help with the Year 4 Multiplication Tables Check? Absolutely. The MTC tests rapid recall of all times tables up to 12×12 under timed conditions. The doubling, pattern recognition, and “known fact” strategies in this article directly prepare children for that format.
Is there a difference between Hit the Button and other maths games? Hit the Button is specifically designed around the UK curriculum for KS1 and KS2, with structured progression across different fact types. Its timed format mimics test conditions and promotes genuine fluency — not just slow calculation.
Conclusion: Small Tricks, Big Results
Mental maths isn’t a talent some children are born with. It’s a skill built through smart practice and the right strategies.
The 10 tricks in this article are used by experienced primary school teachers across the UK every day. They work because they replace slow, effortful counting with elegant, memorable patterns — the same patterns that make mathematically confident adults.
Start with one or two tricks. Practise them until they feel natural. Then add more. Before long, your child won’t just be doing maths — they’ll be thinking mathematically.
And when they jump onto Hit the Button and beat their own high score? That confidence carries into every maths lesson, every test, and every real-life situation that calls for a quick calculation.
You can also explore related topics on this site — including number bonds practice, times tables games, and division facts — to build a complete foundation of mental maths skills.
The best time to start is now. Pick a trick. Try a question. Hit the button.