Comparing Quantities

Every day we compare quantities — prices, scores, populations, distances. But raw numbers alone can be misleading. Anita scored 320 out of 400 and Rita scored 300 out of 360. Who did better? Just looking at 320 vs 300 says Anita did better, but when we calculate the percentage — Anita got 80% and Rita got 83.3% — it becomes clear Rita performed better relative to the total marks. This is the power of percentages and ratios: they allow fair, meaningful comparisons across different totals.

This chapter covers percentages, profit and loss, and simple interest — three of the most directly applicable mathematical concepts in daily life.