Maths

Course · for maths learners

Calculate Smarter

88 Tricks · 15 Minutes a Day

Learn practical calculation techniques through short, visual lessons and interactive practice.

Teaching a child? You do not need to be good at maths yourself — every trick has a script, in the exact words to say out loud.

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The first 7 lessons are free with a free account. No card, nothing charged.

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Calculate Smarter — Free Starter

Try your first 7 calculation tricks for free.

7 tricks · 7 days · 15 minutes a day

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No payment is needed for lessons 1–7, and nothing is charged after them. The full course opens only when you ask for it and we approve it.

Course overview

Five levels. 88 lessons.

From the first multiplication shortcuts to the hardest word problems — one short lesson at a time, each with its own practice.

Total · 88 lessons

Level 1 7 free

Multiplication & Squaring

Shortcuts for ×11, ×5, ×25 and ×9, two-digit products, and squaring in your head.

18 lessons · Lessons 1–18
Level 2 Full course

Division, Addition & Subtraction

Fast division, divisibility tests and remainders, and adding and subtracting from the left.

18 lessons · Lessons 19–36
Level 3 Full course

Percentages & Everyday Maths

Percentages, discounts, fractions and ratios, money, units, time and speed.

18 lessons · Lessons 37–54
Level 4 Full course

Exam Skills, Fractions & Algebra

Estimating and patterns, fraction and decimal operations, algebra identities, roots and cubes.

20 lessons · Lessons 55–74
Level 5 Full course

Advanced Mental Maths

More multiplication methods, HCF and LCM, compound change, interest and word problems.

14 lessons · Lessons 75–88

How it works

Learn. Practice. Challenge. Master.

01

Learn

A short, visual lesson: one diagram, the fast way beside the slow way, and two worked examples.
02

Practice

Eight sums on your own. Check each one, see the working when you slip, and change to a fresh set whenever you like.
03

Challenge

Speed tests at the end of each stage show what has stuck — against the clock.
04

Master

Finish every lesson and pass every speed test to earn your certificate.

A lesson a day

Fifteen minutes a day. One trick at a time.

0—2

Warm-up

Three sums from yesterday. Nothing new. If yesterday has gone, spend the whole session there.
2—7

The new trick

Show the diagram before you say anything. Read the slow way and the fast way side by side.
7—12

They do it

Your job is to say nothing at all. Thinking looks exactly like doing nothing.
12—15

The check

The How Did They Do? box says plainly whether to move on tomorrow or repeat today.

On every trick

Its own chapter, every time.

One diagram

At the top of the chapter, before a single word of method.

Two worked examples

One simple, one with the carry that trips children up.

A script to read aloud

The exact words to say, so you are never caught out.

The mistake to expect

The precise wrong answer children usually produce, printed in advance.

A three-second check

A way to test the answer without redoing the sum.

Eight practice sums

With answers to check after, not during.

The thirteen parts

Part 0

How to teach this book

Read first

Fifteen minutes a day, one trick at a time. What to do when they get it wrong, six things not to say, and where to start depending on the class.

Part 1

Multiplication Shortcuts

Tricks 1—8

The numbers that come up most often — 5, 9, 11, 15, 25 and 99 — plus the criss-cross, which works on any two-digit sum. Do them in order; each one uses the one before it.

Part 2

Squaring & Number Patterns

Tricks 9—18

Squaring saves more exam time than anything else in the book. Square any two-digit number, and several three-digit ones, without a single row of working.

Part 3

Division Made Fast

Tricks 19—27

Dividing by 5, 25, 4, 8 or 50 is really multiplying by something easy and moving a decimal point. Plus the divisibility tests that tell you in advance whether it comes out clean.

Part 4

Addition & Subtraction Speed

Tricks 28—36

Reverse the direction, replace carrying with rounding, and turn subtraction into counting on. Every one can be done without writing anything down.

Part 5

Fractions & Percentages

Tricks 37—48

Discounts, GST, profit and loss, ratios and reverse percentages — the whole of Class 6 to 10 commercial arithmetic, done mentally.

Part 6

Money, Time & Measurement

Tricks 49—54

Where the arithmetic leaves the exam paper and enters ordinary life. Money, clocks, kilometres and averages, and the small trap inside each one.

Part 7

The Exam & Olympiad Edge

Tricks 55—60

How to attack a paper rather than how to calculate. Worth more marks than anything else in the book.

Part 8

Fractions & Decimals: The Operations

Tricks 61—65

The four operations look similar on the page and behave completely differently. This fixes the speed and the confusion at the same time.

Part 9

Algebra & Identities

Tricks 66—70

The Class 8 to 10 identities are not formulas to memorise — they are calculation tools. (a + b)² squares any number in your head.

Part 10

Roots & Cubes

Tricks 71—74

Roots of exact numbers read straight off the page. The last digit gives you one half of the answer, the size gives you the other.

Part 11

More Multiplication Methods

Tricks 75—81

Doubling and halving, numbers just below a hundred, twelves, fours and eights, 125, a long number by a single digit, and the full crosswise method for three-digit numbers.

Part 12

HCF, LCM & Compound Change

Tricks 82—84

The highest common factor by subtraction, the lowest common multiple straight from it, and two percentage changes folded into one multiplier.

Part 13

Word-Problem Shortcuts

Tricks 85—88

Simple interest without the formula, compound interest for two years, time and work by the LCM method, and mixtures by the alligation rule.

Start with 7 free lessons.

7 tricks · 7 days · 15 minutes a day. No card, nothing charged.