A clearer view of every chart.
Free lessons, practical examples and a starting guide for curious beginners.
Two lines. What do you see?
View chart data+
| Observation | Series A | Series B |
|---|---|---|
| 100 | 100 | |
| 110 | 105 | |
| 105 | 110 | |
| 120 | 115 |
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See the context
Read the units, dates and scale before following the line.
Compare with care
A shared starting point helps you compare relative changes.
Explain your thinking
Turn an impression into a reproducible observation.
Small steps. Lasting perspective.
Six practical chapters. Follow the programme or your curiosity.
Ask a better question
Turn a first impression into a question you can actually test.
Check the period
Make sure the observations cover the same stretch of time.
Compare the scales
Explain how units and axes shape the picture.
Put change in percentages
Give different starting values a common reference point.
Look beyond the window
Distinguish a selected movement from a broader pattern.
Write a reproducible note
Leave a clear trail from observation to calculation.
Higher price. Bigger increase?
A: £100.00 → £120.00
B: £200.00 → £230.00
Which series has the greater percentage increase?
Show the answer and reasoning+
A: 20 ÷ 100 × 100 = 20%
B: 30 ÷ 200 × 100 = 15%
Make it make sense.
Good questions. Clear explanations.
What makes a fair comparison?
A comparison needs a common question before it needs a common chart.
Read the articlePercentages are not percentage points
A difference between percentages and a percentage change use different denominators.
Read the articlePut two series on the same starting line
Indexing to 100 compares proportional movement, not original price.
Read the articleFrequently asked questions
Is the school really free?+
All six chapters, ten articles, the glossary and both tools are free to read and use. You do not need an account or payment details.
Do I need to sign up to read the lessons?+
No. Start with any chapter and use the tools immediately. Registration is only for requesting a guide and an introductory call.
What happens on the introductory call?+
The call concerns the free programme and its learning materials, in your selected language. It is not a request for paid-course marketing.
Will this tell me what to buy or sell?+
No. Charts Haven teaches how to read and compare data. The examples are illustrative and are not personal recommendations or forecasts.
Small steps. Lasting perspective.
Free lessons, practical examples and a starting guide for curious beginners.
Request a guide and an introductory call. Lessons are also available without signing up.