📊 Percentage change

Unit 3 · Numbers & functions · 9 min

Percent change = (new − old) ÷ old × 100%. From 200 to 250 is +25%. Successive changes compound: +10% then +10% is +21%, not +20%.

Words in this lesson

• 百分比 (bǎi fēn bǐ) — percentage
• 增长 (zēng zhǎng) — growth

Project: Log your steps for two weeks and compute the percent change from week 1 to week 2.