The formula for calculating simple interest is:

$I = P \cdot r \cdot t$

Where:

• $P$ is the principal amount (the initial amount of money invested or borrowed),
• $r$ is the annual interest rate (expressed as a decimal),
• $t$ is the time the money is invested or borrowed for, typically in years.

Would you like more details on how simple interest works or examples?

Here are 5 related questions:

1. How do you convert an interest rate from a percentage to a decimal?
2. What happens to the simple interest if you increase the time period?
3. How do you calculate total amount (A) using simple interest?
4. What is the difference between simple and compound interest?
5. How would you calculate the principal if you know the interest, rate, and time?

Tip: Always express the interest rate as a decimal when using it in the formula (e.g., 5% becomes 0.05).