The idea
Here's a quick math trick called the Rule of 72: divide 72 by your yearly growth rate, and you get roughly how many years it takes your money to double. Growing at 8%? About 9 years to double (72 ÷ 8). It's a fast way to see why a higher growth rate matters so much. ⚡
Words to know
- Rule of 72
- Divide 72 by the yearly growth rate to estimate how many years it takes money to double.
- Growth rate
- How fast your money grows each year, shown as a percent.
- S&P 500 average
- The S&P 500 (about 500 big US companies) has historically grown roughly 10% a year over the long run.
- HYSA
- A high-yield savings account — a bank account that pays more interest than a normal one.
Try it — no account needed
The Rule of 72: years to double = 72 ÷ rate. Match the rate to how long money takes to DOUBLE.
0 / 4 matched
In the full lesson
- 1Match the pairs
Vine has 107 lessons like this one, each written three ways so a 7-year-old and a 17-year-old both get a version that fits.
Practice with real prices
Real market data, pretend money. Learn how investing actually works without risking a cent.
Start free