Mental maths is often described as the ability to calculate without writing anything down, but for children, it is much more than that. Good mental calculation develops from number sense: understanding how numbers relate to one another, recognising useful patterns, knowing important number facts and being able to choose an efficient way to solve a problem.

This distinction matters because a child can memorise multiplication tables and still struggle with mental maths. Another child may not calculate particularly quickly but may have a strong understanding of numbers and be able to break a difficult calculation into simpler parts. Research on primary mathematics emphasises this flexible understanding of number, place value, calculation strategies and the ability to explain different approaches rather than treating fluency as speed alone.

By around age 10, children are increasingly expected to work confidently with larger numbers, addition and subtraction, multiplication and division, fractions, decimals and simple percentages. Mental calculation becomes easier when these ideas are connected rather than taught as separate tricks. A strong sense of ten, secure place-value understanding and flexible use of known facts provide an important foundation for mental calculation.

The following mental maths tricks for kids are therefore not shortcuts to memorise blindly. Each one is based on a mathematical relationship that children can understand, practise and eventually use independently.

A Better Way to Think About Mental Maths:- Mental maths is not simply about reaching an answer quickly. The stronger skill is recognising relationships between numbers and choosing a strategy that makes the calculation easier. When children can explain why a strategy works, they are building understanding that can transfer to unfamiliar problems.

1. Break Numbers Apart Before Adding Them

One of the most useful mental maths strategies is learning that a number does not always have to be treated as one fixed quantity. Children can split it into parts that are easier to work with mentally.

This builds directly on place value and the ability to compose and recompose numbers. For example, when adding a two-digit number to another number, children can separate the tens and ones instead of trying to process the entire calculation at once. Research-based number-sense activities encourage children to break numbers apart and regroup them because this develops flexible calculation rather than dependence on a single written procedure.

For example, 38 + 27 can be approached as 38 + 20 = 58, followed by 58 + 7 = 65. The calculation becomes easier because the child is using the place value of 27 rather than treating it as an indivisible number.

This strategy is particularly useful for mental addition for children, because the same idea can later be applied to larger numbers and more complicated calculations.

2. Use Number Bonds to Make Ten

A strong understanding of numbers that combine to make 10 is one of the most useful foundations for mental calculation. Children who know these relationships can reorganise calculations instead of relying on counting from one number.

For example, when solving 8 + 6, a child can take 2 from 6 to make 10 with 8. That leaves 4, giving 10 + 4 = 14.

The important learning is not simply remembering that 8 and 2 make 10. Children gradually need to recognise how this relationship can help them solve other calculations. Research on early number sense specifically highlights developing a strong “sense of ten” as an important foundation for place value and mental calculation.

Number bonds also become useful when children work with subtraction, larger additions and eventually fractions and percentages.

3. Learn Doubles and Use Near-Doubles

Doubles are valuable mental maths facts because children can use a known calculation to solve a nearby one. Once a child knows common doubles well, they do not have to calculate every similar addition from scratch.

Suppose a child knows 7 + 7 = 14. If they need to solve 7 + 8, they can recognise that 8 is one more than 7 and think 14 + 1 = 15.

This is known as a near-double strategy. It helps children develop relationships between number facts instead of storing every addition fact as an isolated piece of information. Evidence-informed early mathematics guidance also describes games and activities that help children use near doubles and number bonds as mental strategies.

Parents can strengthen this skill by asking questions such as, “If you know 6 + 6, what could help you solve 6 + 7?” The child then has to explain the relationship rather than simply produce an answer.

4. Round a Number, Calculate, Then Adjust

Numbers that are close to a multiple of 10 or 100 can often be easier to calculate if children temporarily replace them with a round number and then correct the difference.

For example, 49 + 36 can be changed mentally to 50 + 36 = 86. Because 49 was increased by 1, the child then subtracts 1, giving 85.

This strategy is useful because it combines estimation, place value and flexible calculation. The child is learning that a calculation can be transformed into an easier equivalent problem without changing the final mathematical relationship.

The same idea works with subtraction. For 73 − 29, a child might think 73 − 30 = 43, then add 1 back to get 44.

This is one of the more useful mental maths tricks for 8–10 year olds because children are beginning to work with larger two-digit and three-digit numbers where compensation becomes increasingly efficient.

5. Subtract by Counting Up When the Numbers Are Close

Children often learn subtraction as “take away,” but that is not always the easiest way to think about the difference between two numbers. When the numbers are close together, counting up from the smaller number can be much more efficient.

For example, consider 52 − 48. Instead of mentally taking 48 away from 52, the child can think:

48 → 50 = 2

50 → 52 = 2

The total difference is 4.

This strategy connects with the development of a mental number line and counting-on strategies. The U.S. Institute of Education Sciences describes counting on as an increasingly advanced strategy that children can eventually use mentally rather than relying on physical objects or fingers.

It is especially useful for calculations where the difference is small, such as 61 − 58, 103 − 97 or 205 − 198.

Try This Instead:- When a child gets stuck on a calculation, avoid immediately showing them the method. Ask, “Is there another way to make these numbers easier?” This simple question encourages children to look for relationships, rather than assuming every calculation has to be solved using the same procedure.

6. Multiply by 5 Through 10 and Halving

Multiplication becomes easier when children understand how different multiplication facts are related. Multiplying by 5 is a good example because 5 is half of 10.

To calculate 24 × 5, a child can first multiply 24 by 10 to get 240 and then take half, giving 120.

The value of this strategy is not that children have discovered a magic multiplication trick. They are using one known relationship to derive another fact. This approach fits with the broader principle of using known and derived facts for mental multiplication and division.

As children become more confident, the same reasoning can support calculations involving 50, 25 and other related numbers.

7. Double One Number and Halve the Other

Sometimes a multiplication problem becomes easier when one factor is doubled and the other is halved. The product remains unchanged because the two changes balance each other.

For example, 16 × 25 can be transformed into 8 × 50, which is 400.

The child is effectively reorganising the calculation into a form that is easier to handle mentally. This is an excellent example of why mental maths should not be reduced to speed. The valuable skill is recognising which representation makes the calculation simpler.

Research on flexible calculation encourages children to choose strategies according to the particular numbers in front of them rather than applying the same method to every problem.

Not every child will immediately find this strategy intuitive, so it should be introduced once multiplication and division relationships are reasonably secure.

8. Think of 9 as 10 Minus 1

The relationship between 9 and 10 provides another useful mental multiplication strategy. Instead of treating 9 as an isolated multiplication fact, children can think of it as 10 − 1.

For example, for 23 × 9, first calculate 23 × 10 = 230. Then subtract one group of 23: 230 − 23 = 207.

This works because multiplying by 9 is equivalent to multiplying by 10 and removing one group of the number.

The strategy becomes more valuable when children understand why it works. Once they recognise the relationship, they can apply the same reasoning to different numbers instead of memorising a separate procedure.

9. Find 10% First When Working With Simple Percentages

By age 10, many children begin encountering percentages in schoolwork and everyday situations. A useful starting point is understanding that 10% means one tenth.

For example, if a child needs to find 10% of 80, they can divide 80 by 10 to get 8. From there, 20% is 16 and 30% is 24.

The important concept is the relationship between percentages, fractions and division rather than simply memorising percentage rules.

This strategy should be introduced only when the child has a reasonably secure understanding of place value, fractions and division. For younger learners, concrete representations and familiar quantities can provide the foundation before percentage calculations become abstract. Research-based mathematics guidance similarly emphasises developing number relationships and representations before expecting increasingly sophisticated mental calculation.

10. Estimate First and Use the Estimate to Check the Answer

Mental maths should not only help children calculate answers. It should also help them recognise when an answer is unreasonable.

Suppose a child calculates 198 + 304 and gets 702. Before doing the exact calculation, they could estimate that the answer should be close to 200 + 300 = 500. The exact answer is 502, so 702 should immediately look suspicious.

Estimation develops mathematical judgement because children learn to think about the approximate size of an answer before accepting it. Research on number sense highlights estimation, alternative methods and realistic problem-solving as important opportunities for children to develop flexible mathematical thinking.

This habit becomes increasingly useful as calculations become larger. A child does not always need to know the exact answer immediately to recognise whether a result makes sense.

Mental Maths Is About Choosing the Right Strategy

Knowing ten mental maths tricks does not automatically make a child a strong mental calculator. The more important development is learning when a particular strategy is useful.

For one addition problem, breaking numbers apart may be easiest. For another, making a number round first may be quicker. A subtraction problem may be easier through counting up, while a multiplication problem may become simpler through doubling and halving.

This flexibility is an important part of mathematical fluency. NRICH describes effective calculation as involving a “toolbox” of strategies from which learners can select according to the numbers involved. Children can become more accurate when they choose an appropriate strategy rather than applying one method rigidly to every calculation.

Parents can therefore ask “How did you work that out?” rather than focusing only on “What is the answer?” Explaining a strategy makes the child's mathematical thinking visible and gives them an opportunity to compare different approaches.

How Parents Can Practise Mental Maths Without Turning It Into Pressure

Mental maths does not need to become another worksheet-heavy activity. Everyday situations already provide opportunities for children to think about numbers: comparing prices, working out how many items are needed, estimating quantities, splitting snacks, checking change or calculating how much time remains before leaving home.

The important part is to keep the questions appropriate to the child's current mathematical understanding. A five-minute conversation about numbers can sometimes encourage more useful thinking than a long session in which the child is expected to complete calculation after calculation without explaining their reasoning.

Research-based early mathematics guidance also emphasises using meaningful contexts, games, discussion and repeated opportunities to apply mathematical ideas.

A useful home routine might involve:

1. Practising a few known facts such as doubles and number bonds.
2. Giving one mental calculation that requires a strategy rather than rapid recall.
3. Asking the child to explain how they solved it.
4. Comparing two possible strategies when both produce the same answer.
5. Using everyday situations to make mental calculation meaningful.
6. Returning to the same strategy later with slightly different numbers.

The objective is to build confidence and flexibility, not to make children feel that mental maths is a race.

What If a Child Is Still Using Fingers for Mental Maths?

Using fingers is not automatically a sign that a child is weak at mathematics. Physical representations can be a legitimate part of early mathematical development, and children gradually move towards more internal strategies as their number sense develops. The Institute of Education Sciences describes a progression from using objects and direct representations towards increasingly mental forms of counting and calculation.

The more useful question is whether the child is becoming increasingly flexible. If they can solve a calculation with fingers today but begin using known number facts or counting-on strategies later, their mental calculation is developing.

Parents can gently encourage the transition by asking, “Can you think of a way to solve it without counting every one?” rather than taking the child's fingers away or treating their use as a failure.

One Thing to Watch:- A child using their fingers is not necessarily a sign that they are falling behind. What matters more is whether their strategy is developing. If they gradually move from counting every object towards using number facts, counting-on, grouping or other mental strategies, the important shift is already happening.

The Goal Is Flexible Mathematical Thinking

By age 10, children do not need to know every possible mental calculation shortcut. They need a strong enough understanding of numbers to recognise useful relationships and select an efficient method.

That development begins with relatively simple ideas: knowing the numbers within 10, understanding number bonds, recognising quantities, building a strong sense of ten and understanding place value. These foundations gradually support more sophisticated mental addition, subtraction, multiplication, division, estimation and problem-solving.

The best mental maths practice therefore does not ask children to memorise ten tricks and reproduce them as quickly as possible. It encourages them to notice numbers, manipulate them, explain their thinking, compare strategies and check whether an answer makes sense.

A child who can look at 49 + 36 and decide to make 49 into 50 is demonstrating something more valuable than simply knowing an answer. They are recognising a relationship between numbers and deliberately choosing a strategy that makes the calculation easier.

That is the foundation of strong mental maths: not faster counting, but increasingly confident and flexible thinking about numbers.

Frequently Asked Questions

1.What mental maths should a 10-year-old know?

By around age 10, children should be developing fluency with age-appropriate addition, subtraction, multiplication and division while using place value, known facts and flexible strategies to solve calculations mentally. The exact expectations vary by curriculum and individual development, but number sense and flexible calculation are more important than simply performing tricks quickly.

2.How can I improve my child's mental maths skills?

Give children regular opportunities to work with numbers mentally and ask them to explain their strategies. Practising number bonds, doubles, place value, estimation and flexible calculation through everyday situations and games can help make mental maths meaningful rather than purely worksheet-based.

3.Is mental maths about calculating as quickly as possible?

No. Speed can be part of fluency, particularly when recalling well-known number facts, but strong mathematical fluency also involves conceptual understanding, accuracy and the ability to choose and explain an appropriate strategy.

4.Which mental maths tricks should children learn first?

Start with foundational relationships such as number bonds to 10, doubles, near-doubles, counting on and place-value-based decomposition. Once these are secure, children can build towards compensation, flexible multiplication, estimation and other more advanced strategies.

5.How often should children practise mental maths?

Short, regular opportunities are generally more practical than occasional long sessions. Mental maths can be incorporated into games, everyday conversations and simple calculations throughout the day, allowing children to practise strategies repeatedly without making every interaction feel like formal homework.