# Module 2: How to compare data

- [2.1 Absolute numbers versus ratios and percentages](/training-content/module-2-how-to-compare-data/2.1-absolute-numbers-versus-ratios-and-percentages.md)
- [Why we calculate relative numbers](/training-content/module-2-how-to-compare-data/2.1-absolute-numbers-versus-ratios-and-percentages/why-we-calculate-relative-numbers.md)
- [How to calculate relative numbers](/training-content/module-2-how-to-compare-data/2.1-absolute-numbers-versus-ratios-and-percentages/how-to-calculate-relative-numbers.md)
- [Population and comparisons in procurement data](/training-content/module-2-how-to-compare-data/2.1-absolute-numbers-versus-ratios-and-percentages/population-and-comparisons-in-procurement-data.md): When to use absolute numbers VS ratios and percentages