You reach for the calculator for everything
Even things you know you should be able to do.
Courses
Start with three things you can do today
How to do mental math fast
Do the sums in your head before anyone reaches for a phone.
A course on mental arithmetic for everyday life. It covers the handful of techniques fast calculators actually use, how to break numbers into friendly pieces, percentages and tips without a calculator, and how to estimate well enough to catch a wrong answer at a glance.
Open Cadence on the App Store, type the sentence when it asks what you want to learn, and answer a few setup questions. Free to start. Android testers can request early access.
Type this when Cadence asks what you want to learn
I want to do mental arithmetic quickly: tips, discounts, splitting bills and rough estimates. Teach me the tricks people use and get me practising until they are automatic.
Change any word so it fits your situation. The course is built from what you type and a few setup questions.
Start today
Three things you can do before the course exists.
Useful on their own. The course is for when you want the whole skill, not just the first move.
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Work left to right
For 47 plus 38, do 40 plus 30, then 7 plus 8. Fast calculators handle the big parts first and the small parts last.
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Find ten percent, then build the rest
Ten percent of 64 is 6.4, so fifteen percent is 6.4 plus 3.2. Every tip and discount is a multiple of ten percent.
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Round, then correct
49 times 6 is 50 times 6 minus 6. Friendly numbers first, then the adjustment.
- Best for
- Math & numbers
- Prerequisites
- None. Bring the situation you have.
- Course length
- 7 to 30 lessons, sized to your goal
- Lesson pace
- About 10 minutes a day
- Format
- Read it, or play the audio
- Access
- Available on the App Store, with early features and Android testing access
Before the course is built
Setup asks about your situation first.
Lesson 1 opens on the moment you describe, and the examples use your role. For this request, expect questions like these.
- Where do you want to be quicker: shopping, restaurants, work numbers, or generally?
- How are your times tables and basic addition now, honestly?
- Would you rather be exact, or fast and roughly right?
Right for now
If any of this sounds familiar, start here.
Splitting a bill takes a minute of silence
And the whole table waits while you work it out.
You want to sanity check numbers
To know when a figure at work cannot be right.
Course arc
Where the course goes, in order.
Cadence writes the lessons for you, so the exact path follows your answers. This is the ground a course built from this sentence covers.
01 / 06How fast calculators think
Left to right, in chunks, with friendly numbers.
Addition and subtraction
Rounding and compensating.
Multiplication
Doubling, halving and splitting.
Percentages, tips, discounts
One trick that covers nearly all of it.
Estimation
Being roughly right fast.
Practice
Two minutes a day, in the queue.
What changes
What you will be able to do, and what you will stop believing.
You will be able to
Break numbers apart
Rounding, compensating, and working left to right.
Handle percentages
Ten percent, then everything else.
Estimate well
Order of magnitude, and catching errors before they matter.
Make it automatic
Short daily practice that sticks.
Ideas this course corrects
Mental maths is a memory feat
It is a few techniques applied to friendly numbers. Memory holds the tables; technique does the rest.
Estimating is cheating
Estimating is how experts catch mistakes. Exactness comes after the estimate says the answer is plausible.
Course questions
What to know before you start.
How to do mental math fast: what can I do today?
Work left to right. For 47 plus 38, do 40 plus 30, then 7 plus 8. Fast calculators handle the big parts first and the small parts last. Find ten percent, then build the rest. Ten percent of 64 is 6.4, so fifteen percent is 6.4 plus 3.2. Every tip and discount is a multiple of ten percent. Round, then correct. 49 times 6 is 50 times 6 minus 6. Friendly numbers first, then the adjustment.
Is this a fixed course?
No. Cadence builds the course when you type the sentence and answer a few setup questions, so the lessons follow your situation. This page describes what a course built from this request covers. You see the whole path before Lesson 1.
Who is this course for?
A course on mental arithmetic for everyday life. It covers the handful of techniques fast calculators actually use, how to break numbers into friendly pieces, percentages and tips without a calculator, and how to estimate well enough to catch a wrong answer at a glance. It sits under Math & numbers in the Ideas & discovery part of the library.
Do I need any prior experience?
No. Setup asks what you already know and where you want to use it, and the course starts from there. Bring a real situation if you have one; the examples are built around it.
How long does it take?
Courses run 7 to 30 lessons of about 10 minutes, sized to what you asked for. One lesson a day is the intended pace, and you can go faster. Lessons can be read or played as audio.
Does this course award a certificate or degree?
No. Cadence is for practical self-learning and does not award accredited degrees or professional certification.
Start today
Type it, answer a few questions, open Lesson 1.
The sentence to type
I want to do mental arithmetic quickly: tips, discounts, splitting bills and rough estimates. Teach me the tricks people use and get me practising until they are automatic.
Open Cadence on the App Store, type the sentence when it asks what you want to learn, and answer a few setup questions. Free to start. Android testers can request early access.