The Balance Grew, But It Buys Less
by Anonymous · ⭐ 1 · 🍴 0
💰 1,000 in the bank at 3% interest while prices rise 4%, for 20 years. The statement says 1,806, but it only buys 824 worth. The number on the statement and what it can buy are two different values. Move the sliders and watch the two lines part. ⚖️ Second, where it splits. Subtracting inflation from the rate is an estimate; the real answer is a division — the sign always matches, but the size is always smaller than the estimate. Set rate and inflation equal and, after twenty years, your buying power hasn't moved a cent from the principal. 🧺 Third, the basket. Keep money that buys 100 items today and, at 4% inflation, 46 are left after twenty years. Half is gone in 17.7 years — 72 ÷ 4 = 18. The same rule that doubled money also halves it. This app was made with code too · Remix it with your own rate and inflation.
Ready to remix — hit the 🍴 Remix button below. You'll sign up first, then this app is copied into your workspace.
About this app
늘었는데 줄었다 is an interactive financial literacy app about the difference between a growing account balance and declining purchasing power. Adjust the interest rate, inflation rate, and time period to compare nominal savings with what the money can actually buy. Separate tabs explain why subtracting inflation from interest is only an approximation, show the exact real rate through division, and estimate how long purchasing power takes to fall by half.
Use cases
- Learners exploring inflation and real returns
- Adults building practical financial literacy
- Teachers explaining nominal versus real value
- Anyone evaluating whether savings are keeping up with prices
Features
- Interactive sliders for interest, inflation, and years
- Comparison of account balance and purchasing power
- Exact real interest rate versus the subtraction estimate
- Basket visualization showing remaining purchasing power
- Rule-of-72 estimate for time to halve purchasing power
- Three-tab educational flow with reset and sound controls