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It was quick and fast delivery on time. My little one is enjoying her new CGP books. Thank you.

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My order was delivered very fast, and I am very pleased with the workbooks. My son has started practising the questions, which are easy to read and understand for children.

2 days ago
Oluwayemisi Odubanjo

Excellent material that effectively meets my son's academic needs.

2 weeks ago
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With an average score of 4.79 we're rated EXCELLENT
3,663 reviews

The Number Detective (Ages 7-11)

Created By: Tarquin Product Code: EN1986
Subject
Maths Master numbers, calculations, algebra and geometry to solve problems and build logical thinking skills.
Topics
Mental Arithmetic Develop quick calculation skills without calculators, building number confidence and speed for exams
Problem Solving Develop logical thinking and apply maths skills to real-world challenges and multi-step questions
  • SHARPEN logical thinking through cryptic number puzzles that make maths fun
  • Includes Problem Solving & Mental Arithmetic
  • Aligned to Years 3-6 maths curriculum
  • Features systematic detective work that reinforces mathematical vocabulary
  • Standard Delivery within 2-3 working days.
£7.95
With an average score of 4.79 we're rated EXCELLENT
3,663 reviews
Sidra Javed

It was quick and fast delivery on time. My little one is enjoying her new CGP books. Thank you.

2 days ago
Anonymous

My order was delivered very fast, and I am very pleased with the workbooks. My son has started practising the questions, which are easy to read and understand for children.

2 days ago
Oluwayemisi Odubanjo

Excellent material that effectively meets my son's academic needs.

2 weeks ago

About the The Number Detective (Ages 7-11)

The Number Detective transforms maths practice into an engaging puzzle adventure for children aged 7–11 (Years 3–6). If your child finds standard arithmetic drills dull or struggles to apply number skills in new contexts, this puzzle book offers a refreshing alternative that builds logical thinking alongside mental arithmetic mastery. Every cryptic clue demands detective work, encouraging pupils to decode unknown numbers using properties, operations, and systematic reasoning—precisely the problem-solving skills rewarded in Year 6 SATs and throughout the English National Curriculum.

Each puzzle presents a series of mathematical clues that narrow down the identity of a mystery number, reinforcing vocabulary such as factors, multiples, prime numbers, square numbers, and divisibility rules in an active, investigative way. Rather than passively completing worksheets, your child becomes a number detective, testing hypotheses and eliminating possibilities. This hands-on approach deepens understanding of how numbers behave and strengthens mental calculation speed. The puzzles scale naturally across primary years, so whether your Year 3 pupil is mastering place value or your Year 6 child is revising for SATs, the challenges remain accessible yet stretching.

Sample puzzle pages from The Number Detective showing mathematical clues and problem-solving challenges
Inside pages reveal the variety of cryptic clues and logical reasoning tasks that make number properties memorable and fun

The result is a child who views numbers with curiosity rather than apprehension, who can tackle unfamiliar problems with confidence, and who arrives at exam questions ready to think flexibly. Because the book trains both arithmetic fluency and investigative reasoning, pupils gain the twin advantages of speed and strategic insight—essential for timed assessments and real-world maths. Published by Tarquin and available as a physical book, The Number Detective slots easily into after-school routines, weekend enrichment, or homework sessions, offering screen-free practice that keeps motivation high.

This puzzle book suits any Year 3–6 pupil who enjoys challenges, needs a break from repetitive exercises, or benefits from seeing maths as a game rather than a chore. Parents appreciate the self-directed format: children can work independently, checking their reasoning as they go, while you support from the sidelines without needing to teach new concepts. It's an ideal companion to formal revision guides, adding variety and depth to your home learning toolkit.

  • Cryptic number puzzles that develop logical reasoning and problem-solving skills across Years 3–6
  • Reinforces curriculum vocabulary including factors, multiples, primes, and square numbers in an active, investigative format
  • Builds mental arithmetic fluency and strategic thinking for Year 6 SATs and beyond
  • Screen-free, self-directed practice that keeps children engaged and motivated
  • Physical book published by Tarquin, suitable for independent work or guided sessions at home
Product Code Publisher ISBN 13
EN1986 Tarquin 9781899618330
The Number Detective (Ages 7-11) Look Inside Image 1
The Number Detective (Ages 7-11) Look Inside Image 2
Zachary Lucas

The Number Detective is a fantastic resource! It engages students in captivating math challenges, boosting their problem-solving abilities. My pupils feel well-prepared for their upcoming exams, thanks to this invaluable book.

Jasper Green

A super clever book that's boosted my granddaughter's maths prowess! She's exam-ready and brimming with confidence, thanks to these fun, mind-stretching puzzles. Highly recommended!

Jasper Matthews

Great prep for exams, builds skills and confidence.

Frequently Asked Questions

Is this suitable for my child?

The The Number Detective (Ages 7-11) is absolutely perfect for children in Year 3, Year 4, Year 5 or Year 6 studying the national curriculum in England.

It is also very useful for children in the devolved nations of Wales, Scotland and Northern Ireland that study similar curriculums.

Finally, the The Number Detective (Ages 7-11) is also very useful for children studying outside of the UK on comparable international curriculums such as the Cambridge Primary Curriculum or The Pearson Edexcel International Primary Curriculum.

How much is delivery?

Standard delivery within the UK is free of charge for all orders over £30. Orders below £30 carry a £3.95 delivery charge.

We also deliver to over 200 countries across the world! Delivery fees are charged according to the weight of the parcel and are as competitive as we can possibly offer. This is calculated in the checkout where you are given a full delivery cost before we ask for payment.

When will I receive my order?

Orders shipped within the UK are normally delivered within 2-3 working days.

International orders typically take up to 10 working days assuming all relevant import duty payments are successfully processed on time.

How do I track my delivery?

When your order is shipped, we will send you an email notification that includes your tracking number and a link to the courier's website for you to track your delivery.

Which couriers do you use?

At Exam Ninja, we have no patience for slow, unreliable couriers. As such, we use the tried and trusted couriers, Royal Mail and DPD, for all our deliveries within the UK.

For our global deliveries, we only use the fully tracked couriers DPD, FedEx, TNT, ParcelForce and UPS.

Do you ship internationally?

Yes! We ship to over 200 international destinations using fully tracked international courier services.

The countries we currently ship to are:

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