“Quick, what is 98 plus 57?” A Class 4 student reaches for a pencil. Her friend simply says, “One fifty-five,” and grins. The difference is not magic. It is a handful of strategies that turn awkward sums into easy ones. Mental maths builds confidence, speeds up written work and makes numbers feel friendly. This guide shares simple, tested strategies for primary students, with worked examples and home practice ideas, for families exploring the best CBSE school in South Bangalore.

Why mental maths matters

• It builds number sense: a feel for how numbers behave.
• It speeds up written work and exam problems.
• It supports estimation and checking answers.
• It makes maths feel less scary.
• It strengthens memory and flexible thinking.

The goal is understanding, not tricks without meaning. Always ask your child, “Why does that work?”

Strategy 1: Make a friendly number

Round to a nearby ten or hundred, then adjust.

• 98 + 57: take 100 + 57 = 157, then subtract the 2 you added. Answer: 155.
• 47 + 38: take 47 + 40 = 87, then subtract 2. Answer: 85.
• 83 − 39: take 83 − 40 = 43, then add 1 back. Answer: 44.

Children learn that the rounding step is a trade, and they fix it afterwards.

Strategy 2: Break apart numbers

Split numbers into tens and ones (or hundreds, tens and ones).

• 35 × 12: split 12 into 10 and 2. 35 × 10 = 350, and 35 × 2 = 70. Together: 420.
• 46 + 27: add tens first, 40 + 20 = 60, then ones, 6 + 7 = 13. Total: 73.

Strategy 3: Use the ten trick for nines

To multiply by 9, multiply by 10 and subtract once.

• 9 × 7: 10 × 7 = 70, minus 7 = 63.
• 9 × 8: 80 − 8 = 72.

A finger trick also works for the nine times table, and it is worth showing too.

Strategy 4: Double and halve

Sometimes doubling one number and halving the other makes the sum easier.

• 25 × 16: half of 16 is 8, double of 25 is 50. Now 50 × 8 = 400.
• 15 × 14: half of 14 is 7, double of 15 is 30. Now 30 × 7 = 210.

Strategy 5: Think of multiplication facts as groups

Linking facts helps recall.

• If 6 × 5 = 30, then 6 × 6 is 30 plus one more 6, which is 36.
• If 8 × 4 = 32, then 8 × 8 is double that, 64.

Strategy 6: Count on and count back

For small gaps, jump up or down.

• 62 − 58: count up from 58 to 62, four steps. Answer: 4.
• Change from 100: if an item costs 63, count up to 70 (7), then to 100 (30). Change: 37.

This suits money problems well. See money habits for kids for everyday practice.

Strategy 7: A pattern for older primary children

To multiply a two-digit number by 11, add the two digits and place the sum in the middle.

• 11 × 34: 3 and 4 add to 7, so the answer is 374.
• 11 × 52: 5 and 2 add to 7, so the answer is 572.

If the digits add to ten or more, carry one into the first digit: 11 × 48 gives 4, then 12, then 8, which becomes 528. Explain why it works with a diagram, so it is not just a trick.

A quick reference

Strategy	Good for	Example
Friendly number	Adding or subtracting near a ten	98 + 57 = 155
Break apart	Multiplying by tens plus a small number	35 × 12 = 420
Nines via ten	Nine times table	9 × 7 = 63
Double and halve	Products involving 5, 15, 25	25 × 16 = 400
Count on	Change and small differences	100 − 63 = 37
Eleven pattern	Two-digit times 11	11 × 34 = 374

Making practice fun

1. Daily number talk. Ask one question at breakfast or in the car.
2. Games. Card games, dice, dominoes, number bingo.
3. Shop and cook. Estimate bills, halve recipes.
4. Beat the clock gently. Use friendly timers for fluency, not pressure.
5. Explain it back. Ask, “How did you work that out?”
6. Celebrate different methods. There is rarely one right way.

Practise little and often. See spaced repetition explained for how short, repeated practice helps memory, and active recall for school students for retrieval ideas.

Building the foundation

Mental strategies rest on strong basics: place value, number bonds, times tables and the ability to count in steps. If your child finds these difficult, go back a step and use objects, drawings and games. Persistent struggles with numbers may reflect a learning difference. See dyslexia in school children for how to seek help, and discuss concerns with the teacher.

Link to school learning

Good schools teach mental maths alongside written methods and concrete materials, and link it to problem-solving. See the school’s areas of curriculum focus page for how it describes learning areas, and the CBSE school visit checklist for ways to see this in a classroom.

Questions to ask a school

1. How do you teach number sense and mental maths?
2. How do you use concrete materials and games?
3. How do you support children who find maths hard?
4. How do you stretch children who are ahead?
5. How do you involve parents in maths practice?

Use these with our 15 questions to ask a school before admission.

Frequently asked questions

At what age can children start mental maths?

From early years, through counting games and number talk.

Are tricks better than written methods?

Both matter. Mental strategies support, and do not replace, written methods.

My child is slow at mental maths. Is that a problem?

Speed grows with practice. Focus on understanding first.

How long should daily practice be?

Five to ten relaxed minutes is plenty.

What if my child hates maths?

Use games, real-life examples and praise for effort to rebuild confidence.

Choose a school that makes numbers feel friendly

If you are exploring the best CBSE school in South Bangalore, read our guide to the best CBSE school in South Bangalore, the best school in South Bangalore and the school’s admission guidelines.

Image suggestions

• Child using a number line to count on from 58 to 62. Alt text: Child counting on a number line
• Family playing a dice game with score sheets. Alt text: Family playing a maths dice game
• Teacher showing a double-and-halve example on a board. Alt text: Teacher demonstrating a mental maths strategy