🔢 Math Calculator

📐 How It Works

Models quantities that grow proportionally to their current size — compound interest, population growth, viral spread, and radioactive decay.

🔢 Worked Examples

• $1,000 at 7% for 10yr = $1,967 (annual compound)
• 1% daily growth for 1yr = 1.01^365 ≈ 37.8× (the "1% better" effect)
• Population doubling time: 70/r% (Rule of 70)

📋 Common Use Cases

• Compound interest and investment projections
• Population and epidemiological modelling
• Viral content spread estimation
• Nuclear physics — radioactive decay curves

💡 Did You Know?

The "Rule of 70": divide 70 by the annual growth rate (%) to estimate the doubling time. At 7% annual growth, money doubles in ~10 years. At 3% inflation, prices double in ~23 years.

⚠️ Common Mistake

Confusing "grows by 5%" (×1.05 each period) with "grows to 5%" (×0.05 — a decrease). "By" means you add, "to" means you replace.