The Importance of Strong Mental Arithmetic for 11 Plus Success

Let’s explore why mental arithmetic matters so much, what it looks like in 11 Plus maths questions, and how you can help your child hone these vital skills at home.

The GL 11 Plus maths paper is made up almost entirely of word problems. Every question requires children to:

Step 1: work out what sum, or sums, the question needs them to do.

Step 2: carry out the calculations quickly and confidently, without a calculator.

Many children struggle with step 1 - understanding the structure, but once they’ve cracked that, the actual arithmetic is usually quite simple - if they can do it mentally.

Let’s look at two typical examples.

A jumper is reduced by 25% in a sale. The sale price is £30. What was the original price?

At first glance, this question might look quite tricky, but once the child understands the method, the maths is extremely clean:

• 25% was taken off, so £30 represents 75%.

• To find 25%, divide 75% by 3: £30 ÷ 3 = £10.

• So the original price was: £30 + £10 = £40.

Or using another mental maths method:

• 75% = ¾

• ¼ of the original price = £10.

• So the full price = 4 × £10 = £40.

This is the perfect example of a question where:

• The method takes thinking.

• The arithmetic should take seconds.

Paula goes for a bike ride. She cycles for 1 hour and 12 minutes. A quarter of her bike ride is uphill. How many minutes does she spend cycling uphill?

• Convert to minutes: 60 + 12 = 72 minutes.

• Find ¼ of 72: 72 ÷ 4 = 18 minutes.

Again, knowing how to tackle the question requires reasoning - but the maths should be instant.

Some parents assume a tutor will “teach” mental maths. But mental arithmetic isn't something that can be learned in one-hour sessions. It’s like fitness - you don’t get fit by going to the gym once a week. What works is short, regular, daily practice.

Even 5 minutes a day makes a big difference. 10 to 15 minutes a day, 5 times a week, is ideal.

Before Years 4 or 5, the best preparation for the 11 Plus maths test isn’t early tutoring - it’s developing fast, confident mental arithmetic. This skill underpins everything else.

Instant recall of times tables, without chanting, counting up, or using fingers, is one of the strongest predictors of success in 11 Plus maths. When a child knows that:

• 7 × 6 = 42

• 9 × 8 = 72

• 4 × 12 = 48

without pausing to work it out, their brain can focus on the reasoning part of a problem rather than the calculation.

A child who hesitates on basic multiplication will struggle to keep up with the pace of an 11 Plus test, whereas a child with quick recall gains a huge time advantage.

Number bonds are pairs of numbers that fit together to make a target total - usually 10, then 20, and later 100. For example, children should instantly know that:

• 7 + 3 = 10

• 14 + 6 = 20

• 60 + 40 = 100

Strong number-bond knowledge means your child doesn’t need to stop and work out basic sums - they just know them  automatically. This frees up thinking time for the trickier part of an 11 Plus question: understanding what the problem is asking.

In short: fast number bonds = fast, accurate mental maths, which is essential for beating the clock in the 11 Plus.

A deep understanding of place value means a child knows how numbers behave when they grow, shrink, or shift position. It helps children instantly see that:

• If 2 + 8 = 10, then 20 + 80 = 100

• 0.2 + 0.8 = 1

• 300 ÷ 3 = 100

This skill is essential for mental maths because it removes the need for written methods. Children can scale numbers up or down, move between units and tens, work with decimals or money, and check whether an answer “looks right.”

Place value is one of the foundations supporting almost all rapid mental calculations.

Quick mental addition and subtraction is essential for keeping pace in the 11 Plus. Children should be able to solve questions like:

• 47 + 35

• 68 − 29

• 54 + 28

without needing to write them down.

This skill also helps with “bridging” through 10 or 100:

• 58 + 7 = 58 + 2 + 5 = 60 + 5 = 65

• 103 − 18 = 103 − 3 − 15 = 100 - 15 = 85

It’s hugely important in word problems, money questions, multi-step problems, and estimation. When addition and subtraction are automatic, everything else speeds up.

Halving and doubling are mental-maths superpowers. A child who can instantly halve 86, or double 37, gains speed across the entire maths paper. These are the kinds of operations that appear repeatedly in GL questions, hidden inside longer word problems.

Fact families help children recognise the relationships between multiplication and division. For example, if a child knows:

• 6 × 7 = 42

then they automatically know:

• 7 × 6 = 42

• 42 ÷ 6 = 7

• 42 ÷ 7 = 6

This means fewer things to memorise and far quicker problem-solving. Fact families help children jump between operations confidently and avoid common division mistakes. They also play a big role in checking the accuracy of answers under time pressure.

Estimation is a powerful accuracy tool - especially in a timed exam. It helps children:

• Avoid silly mistakes.

• Check whether their answer is sensible.

• Spot when they’ve added instead of subtracted (or vice versa).

• Round numbers quickly to simplify calculations.

• Move faster through multi-step problems.

A child who can quickly estimate, for example, that 49 × 6 should be “roughly 300,” will spot immediately if their incorrect answer is wrong. It provides confidence and stops panicked second-guessing.

Dice are brilliant for quick-fire mental maths because each roll creates new, unpredictable combinations. You can use them for:

• Addition practice: roll two dice, add them instantly.

• Subtraction: roll two dice, subtract the smaller from the larger.

• Multiplication: roll two dice and multiply (perfect for times tables fluency).

• Three-dice challenges: roll three dice and ask your child to reach a target number using any operations.

You can make it competitive by setting a timer or by playing “first to 10 points” - one point for each correct answer. Children love the unpredictability, and it turns practice into a game instead of a chore.

A simple deck of cards is one of the best mental maths tools. Try these activities:

• Two-card multiplication: turn over two cards and multiply.

• Addition race: turn two cards and add them - fastest wins the round.

• Make the biggest number: turn over three cards and arrange them to create the largest (or smallest) possible number - brilliant for place value.

• Target total: choose a target number and use the cards to reach it (eg. make 24 using any operations).

Card games are fast, fun, and naturally encourage mental calculation and number flexibility.

Timed challenges build speed and confidence quickly - children often underestimate what they can do in just 60 seconds. Examples include:

• How many times tables can you answer in one minute?

• How many doubles can you do in 60 seconds?

• How many addition facts under 20 can you get?

Children love beating their own score. This turns practice into a fun personal challenge rather than something that feels like schoolwork.

Apps are brilliant for short bursts of practice:

• Hit the Button is excellent for number bonds, doubles, halves, and times tables.

• Maths Frame has fantastic curriculum-linked games.

• Times Tables Rock Stars builds speed and confidence through timed sessions and rewards.

Just 10 minutes a day can make a huge difference - and it feels like play, not homework.

Practise mental maths on the school run, in the car, or while walking the dog. No worksheets, no sitting still - just quick questions woven into normal life.

Examples:

• What’s double 18?

• What’s half of 86?

• What’s 7 × 6?

• Count in 8's from 16.

• If we walk for 12 more minutes, how long will we have we walked altogether?

Walking maths is perfect for children who don’t enjoy sitting down to practise - the movement makes it relaxing and stress-free.

Daily life is full of chances to build mental maths without it ever feeling like work. Examples include:

• Cooking: halving or doubling ingredients; converting grams to kilograms; timing recipes.

• Shopping: estimating totals; working out change; comparing prices.

• Journeys: estimating travel time; reading timetables; calculating how long is left.

• Money: understanding coins and notes; calculating savings; splitting bills.

• Telling the time: being able to tell the time instantly on both analogue and digital clocks, and converting between times written in 24 and 12 hour format. These skills are vital for the 11 Plus maths test.

Real-life maths helps children see that numbers are useful, not just part of an exam - and helps them develop the flexible thinking needed for word problems.

These turn mental maths into detective work. Examples:

• Something × 6 = 48. What’s missing?

• Something + 27 = 40

• 72 ÷ something = 9

• The answer is 36. What could the question be?

Broken calculations strengthen reasoning skills and deepen understanding of relationships between operations, something tested heavily in the 11 Plus.

Children also enjoy inventing their own puzzles for you to solve!

If there is one thing your child can do that will dramatically improve their 11 Plus maths performance, it is this:

👉 Build strong, fast, accurate mental arithmetic.

• It makes word problems easier.

• It boosts speed and accuracy.

• It even supports Verbal Reasoning.

• And it builds enormous confidence.

At Club 11 Plus, mental arithmetic sits at the heart of everything we teach, because we see how powerfully it transforms a child’s progress.

It doesn’t require hours of tutoring. Just simple, regular, enjoyable practice at home.

Strong mental arithmetic is the foundation of 11 Plus maths success - and every child can master it!

If you'd like to find out more about how Club 11 Plus can help your child on their journey towards the 11 Plus test, click here to visit our website.

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