Rate — the percentage
Explore why interest = P×R×T.
In this lesson
Rate — the percentage is part of Simple Interest Math. This preview shows how interest-growth connects to everyday family decisions such as earning, saving, spending choices, goals, approvals, or parent-guided money conversations inside Progress Penguin.
Today’s money mission
Imagine this situation: Two savings accounts: Account A at 6%, Account B at 9%. You save 40000 in local currency for 1 year.
What you need to know
Interest = P×R×T. Rate and interest are directly proportional — double the rate, double the interest (with same principal and time). Comparing rates before saving or borrowing is always worthwhile.
Real-life example
Real-life money moment: You borrow 50000 in local currency at 24% APR for 1 year. A bank offers the same loan at 18% APR.
Progress Penguin connection
Find the annual interest rate for your savings account. Divide it by 12 to get the monthly rate. Divide by 365 to get the daily rate. Apply each to your current savings balance. That is how much your balance earns per day, per month, and per year.
Activity preview
Try the money challenge
Match each key term from this lesson to its definition. The trickiest pair connects to: interest = P×R×T. If a match feels wrong, reread the guided explanation and try again.
Practice adding money to savings
Open Requests and make a deposit request into savings so you can see how saving starts. Parent approval can happen later.
Quiz preview
If a rate is 6% per year and you save for 1 year:
Two savings accounts: Account A at 6%, Account B at 9%. You save 40000 in local currency for 1 year. How much more does Account B earn?