A child may be able to solve a mathematics problem when given a sheet of paper, yet struggle when asked a simple question such as:
“What is 27 + 18?”
They may pause, reach for their fingers, start writing, or simply say, “I don’t know.”
For many parents, this can be confusing.
“My child understands mathematics in school, so why is mental math so difficult?”
The truth is that struggling with mental math does not automatically mean that a child is poor at mathematics.
Mental calculation requires several skills to work together — including number sense, concentration, memory, visualization, accuracy and confidence.
The good news is that these skills can be developed through appropriate teaching and regular practice.
What Is Mental Math?
Mental math, also called mental arithmetic, is the ability to perform mathematical calculations in your head without relying primarily on paper, a calculator or physical counting aids.
For example, a child may be asked:
35 + 27 = ?
Instead of writing the calculation down, the child might mentally break it apart:
35 + 20 = 55
55 + 7 = 62
The ability to do this comfortably develops over time.
Mental math is therefore not simply about being fast.
It involves understanding numbers and knowing how to work with them mentally.
Why Is Mental Math Difficult for Some Children?
Children learn differently, and there can be several reasons why mental calculation feels challenging.
1. They Have Not Developed Strong Number Sense
Number sense is a child’s understanding of numbers, quantities and relationships between numbers.
A child who understands that 48 is close to 50 may find certain calculations easier than a child who sees every number as an isolated figure.
For example:
48 + 19
A child with good number sense may think:
48 + 20 = 68
68 – 1 = 67
Instead of treating the calculation as a completely new problem, the child recognizes a useful relationship between the numbers.
Developing this understanding can make mental calculation easier.
2. They Rely Too Much on Written Calculations
Writing calculations down is an important mathematical skill.
However, if a child always depends on writing every step, mental calculation may feel unfamiliar.
This does not mean written mathematics is bad.
Rather, children can benefit from developing both abilities:
Written calculation + mental calculation
The goal is to give children different ways of approaching a mathematical problem.
3. Working Memory Can Become Overloaded
Mental calculations require children to hold information in their minds while manipulating it.
Consider:
47 + 26
A child might mentally calculate:
47 + 20 = 67
and then remember 67 while adding the remaining 6.
For some children, keeping intermediate numbers in their minds can be challenging.
With structured practice, children can become more familiar with calculation patterns and strategies.
4. Lack of Practice
Mental calculation is a skill.
Like reading, typing, playing an instrument or learning a sport, it generally becomes easier with practice.
A child who rarely performs calculations mentally may naturally feel uncomfortable when asked to do so.
The answer is not necessarily to give the child hundreds of difficult questions.
Instead, short and consistent practice can help build familiarity.
5. Mathematics Anxiety
Sometimes the problem is not the calculation itself.
It is the child’s confidence.
A child who repeatedly hears things like:
“You are not good at mathematics.”
may eventually begin to believe it.
That belief can affect how the child approaches mathematical problems.
When a child expects to fail, even a simple calculation can feel intimidating.
Parents and teachers can help by creating an environment where mistakes are treated as part of learning.
Instead of:
“You got it wrong again.”
try:
“Let’s look at it again. Which part became confusing?”
The difference may seem small, but encouragement can influence how children approach challenges.
6. Difficulty Concentrating
Mental math requires attention.
If a child is distracted while a series of numbers is being presented, they may forget part of the calculation before they have an opportunity to solve it.
For example:
12 + 8 + 15
The child needs to remember the numbers and process them in sequence.
Regular activities that require children to listen, remember and respond can help them practise sustained attention.
Does Being Slow at Mental Math Mean a Child Is Bad at Mathematics?
Not at all.
Speed and mathematical understanding are not the same thing.
A child may take longer to calculate but still have a strong understanding of mathematical concepts.
Another child may calculate quickly but struggle when asked to explain why an answer is correct.
This is why parents should avoid judging mathematical ability based entirely on speed.
Accuracy, understanding, reasoning and confidence matter too.
Speed can improve with practice, but it should not become the only measure of success.
Mental Math vs Written Calculation
Both are valuable.
Written calculation allows children to organize their thinking and work through complex problems step by step.
Mental math encourages children to manipulate numbers mentally and recognize relationships between them.
Consider:
25 + 25
A child does not necessarily need to write this down.
They can recognize that two groups of 25 make 50.
As calculations become more complex, written methods become increasingly useful.
The important thing is helping children know when and how to use different strategies.
Can Abacus Training Help With Mental Math?
This is where abacus-based learning can be particularly interesting.
An abacus gives children a physical representation of numbers.
Instead of seeing numbers only as written symbols, children can represent quantities using beads and learn specific calculation techniques.
At the beginning, the child physically interacts with the abacus.
With continued practice, the child can gradually learn to visualize the abacus mentally.
The physical beads are no longer necessary for every calculation.
This transition can support the development of mental calculation skills.
How Visualization Can Support Mental Calculation
Imagine a child looking at an abacus.
They see the position of the beads representing a number.
After practising repeatedly, the child can begin to form an image of that abacus in their mind.
When presented with a calculation, they can mentally imagine the bead movements.
This is different from simply memorizing answers.
The child is learning to work with a mental representation of numbers.
Visualization is one of the reasons mental abacus training can be useful as part of a broader mathematics-learning programme.
What Skills Can Abacus Practice Develop?
Depending on how it is taught and practised, abacus learning can provide children with opportunities to develop several related skills.
Mental Calculation
Children practise performing calculations without relying entirely on written work.
Concentration
They need to focus on numbers, instructions and calculation steps.
Memory
They practise retaining numbers and sequences while solving problems.
Visualization
Mental abacus exercises encourage children to form and manipulate visual representations of numbers.
Accuracy
Children learn that getting the correct answer matters alongside speed.
Confidence
As children practise and see their progress, they may become more comfortable working with numbers.
These skills can support mathematics learning, although they should be developed alongside broader mathematical understanding.
Simple Mental Math Activities Parents Can Try at Home
Parents do not need expensive equipment to encourage mental math.
Everyday situations can become opportunities to practise.
Activity 1: Shopping Calculations
While shopping, give your child a simple challenge.
For example:
“This item costs ₦500 and this one costs ₦300. How much are they together?”
As the child becomes more comfortable, increase the difficulty.
Activity 2: Number Bonds
Ask questions such as:
“What number do we need to add to 7 to make 10?”
Then gradually increase the numbers.
Activity 3: Mental Addition
Give your child two numbers and ask them to calculate mentally.
For example:
16 + 9
Encourage them to explain how they reached the answer.
Activity 4: Everyday Estimation
Ask:
“If one bottle costs ₦400, approximately how much would three bottles cost?”
This introduces children to estimation and multiplication in an everyday context.
Activity 5: Number Patterns
Ask children to continue patterns:
2, 4, 6, 8, ___
Then increase the challenge:
5, 10, 15, 20, ___
Number patterns can help children recognize relationships between numbers.
How Parents Should Respond When a Child Gets an Answer Wrong
Mistakes are part of learning.
If a child gives the wrong answer, immediately providing the correct answer may not always be the most useful response.
Instead, ask questions.
“How did you get that answer?”
or:
“Can you try another way?”
This gives you an opportunity to understand where the child is struggling.
Perhaps they misunderstood the question.
Perhaps they forgot one number.
Perhaps they used an inefficient strategy.
Once the problem is identified, it becomes easier to help.
Should Children Focus on Speed?
Speed should come after understanding and accuracy.
If a child is still learning how to solve a calculation, constantly demanding a faster answer may create unnecessary pressure.
A better progression is:
Understand → Practise → Become accurate → Build confidence → Increase speed
As children become familiar with calculation strategies, speed can naturally improve.
When Should Parents Consider Structured Math Training?
If a child consistently struggles with calculations despite regular support, parents may consider additional structured learning.
This does not necessarily mean that something is wrong with the child.
Different children sometimes need different learning environments, teaching approaches or amounts of practice.
A structured programme can provide:
- Regular lessons
- Guided practice
- Progressive difficulty
- Feedback
- Repetition
- Opportunities to develop mental calculation
The key is finding an approach that matches the child’s learning needs.
How SIMA Abacus Approaches Mental Calculation
At SIMA Abacus, the goal is not simply to teach children how to move beads.
The learning process introduces children to numbers through structured abacus activities and gradually encourages them to develop mental calculation and visualization skills.
Through regular practice, children can progress from working with the physical abacus toward mentally visualizing calculations.
The broader aim is to help children become more comfortable and confident when working with numbers.
Helping Your Child Develop a Better Relationship With Mathematics
Perhaps one of the most important things parents can do is change the way mathematics is presented at home.
Mathematics does not have to be associated with fear, pressure or punishment.
It can be presented as a puzzle.
A challenge.
A game.
A practical skill.
When children are encouraged to ask questions and make mistakes without embarrassment, they can become more willing to engage with difficult problems.
And when they experience small successes, those successes can build confidence.
If your child struggles with mental math, don’t immediately conclude that your child is bad at mathematics.
Mental calculation involves several skills working together, and these skills can develop with appropriate instruction, patience and practice.
Strong number sense, concentration, memory, visualization, accuracy and confidence can all contribute to better mental calculation.
Abacus-based learning is one structured approach that can help children practise these areas while developing mental arithmetic skills.
The goal should not simply be to make children calculate faster.
The bigger goal is to help them become confident, thoughtful and capable learners who are comfortable working with numbers.
Because sometimes, the biggest change in a child’s mathematics journey begins with something as simple as replacing:
“I can’t do this.”
with:
“Let me try.”
About SIMA Abacus
SIMA Abacus provides structured abacus-based learning designed to support children’s mathematical development through calculation, visualization and regular practice.
For children, mathematics is not just about getting the right answer. It is also about developing the confidence and skills to approach problems, think clearly and keep trying.