This module is about answering questions that give you data: a table, a short extract or a list of figures. You need to calculate carefully, describe what the numbers show, connect them to an economic idea and write a balanced judgement.
These skills appear throughout IGCSE Economics. Check the current syllabus on the Cambridge subject page for the exact assessment details for your exam year.
What do you need to know first?
You should be comfortable with percentages and with the basic models in supply and equilibrium and demand relationships. If elasticity calculations are still shaky, look at elasticity as well, because percentage change sits at the heart of it.
One orienting example
A fictional business, Tessa Mill, recorded sales of RM80,000 in Year 1, RM100,000 in Year 2 and RM95,000 in Year 3.
From Year 1 to Year 2 sales rose by RM20,000. As a percentage of the starting figure, 20,000 ÷ 80,000 × 100 = 25%. From Year 2 to Year 3 sales fell by RM5,000, and 5,000 ÷ 100,000 × 100 = 5%.
A good description would read: “Sales rose overall from RM80,000 to RM95,000, an increase of 18.75%, although they fell by 5% in Year 3.” The number is checked (15,000 ÷ 80,000 = 0.1875), the direction is stated, and the exception is named. That is the habit this module builds.
In what order should you study the lessons?
- Select an appropriate percentage base: every later skill uses percentages, so start by choosing the right denominator.
- Describe a trend with a qualification: turn figures into a precise sentence that includes exceptions.
- Build a chain from evidence to a model: connect what the data shows to supply and demand reasoning.
- State an alternative explanation: learn why the data rarely proves one cause.
- Write a balanced economic analysis without unsupported political verdicts: finish with judgement that stays inside the evidence.
Then try the mixed practice set. The percentage-base explorer and the ratios tool with interpretation limits support the lessons, and the elasticity and percentage-base tutor helps with the first lesson.
What are the common traps?
- Dividing by the wrong number. A change is usually measured against the starting value, not the ending one.
- Repeating figures without comment. Quoting “2019: 100, 2020: 104” is not a description. State the direction, size and any exception.
- Treating a correlation as proof. Two figures moving together may share a third cause.
- Slipping into opinion. Words like “wrong”, “unfair” or “obviously better” need evidence, or they cost you credit.
- Mixing up percentages and percentage points. A rate moving from 5% to 6% is a 1 percentage point rise, and also a 20% rise in the rate.
How should you use the practice set?
Work through the lessons first. Then attempt the practice questions on paper, with a calculator for the arithmetic, and open each solution only after you have written your own. Record each slip in the mistake log and retest queue and retry that type of question a few days later.
All businesses, economies and figures in this module are invented, so the answers rely on the data given and never on real events.