Published 30 Jun 2026
E-Math Statistics and Probability Mistakes: Tables, Averages, and Counting
A focused guide to common E-Math statistics and probability mistakes, including averages, frequency tables, cumulative frequency, probability, and counting.
Quick answer
Statistics and probability mistakes often come from reading the table wrongly, using the wrong total, or treating averages and probabilities as formula-only tasks.
Key takeaways
- Identify the total and category before calculating.
- Check whether data is raw, grouped, cumulative, or weighted.
- In probability, define the event clearly before counting.
How this guide was written
Mentora writes these guides from Singapore GCE O-Level E-Math diagnostic patterns: the first step that breaks, the prerequisite behind it, and the next repair task a student can practise. The advice is meant to help students and parents choose better revision actions, not to replace school guidance or official SEAB syllabus requirements.
Read Mentora's methodology and editorial standardsRead the data structure first
Statistics questions can look straightforward, but the table structure matters. Raw data, frequency tables, grouped data, and cumulative frequency need different handling.
Many errors happen before the formula is even chosen.
Common probability traps
Probability mistakes often come from using the wrong denominator, double-counting, or not separating cases clearly.
Students should write the event in words before calculating.
- Check whether replacement is involved.
- Use the correct total after each draw.
- Separate 'and' from 'or' cases.
- Check whether outcomes are equally likely.
Review by mistake type
After marking, classify whether the mistake was table reading, formula choice, arithmetic, or event counting.
That makes the next practice task much clearer than simply doing another mixed statistics set.
Not sure what to practise first?
Take the free E-Math diagnostic to see whether the next task should repair a foundation, review a fading skill, or move into a harder question.
FAQ
Why do I make mistakes in E-Math statistics?
The issue is often reading the table structure wrongly or using the wrong total. Identify the data type before calculating.
How do I improve E-Math probability?
Define the event, count favourable outcomes carefully, check the denominator, and separate multi-step cases before simplifying.
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Keep going with the next guide that matches the mistake pattern or revision decision you are working on.
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