The formula for calculating simple interest in a savings account is Interest = P * R * T. Multiply the account balance by the interest rate by the time period.

If you can add two 3-digit numbers, then you can use the same method to add 4-digit numbers together. Just remember to add on the number that you have regrouped.

Interest is defined as the cost of borrowing money or the rate paid on a deposit to an investor. It can be classified as simple interest or compound interest.

Interest on a savings account can help your money grow more quickly. Learn how interest works on savings accounts and the effect of compounding.

Activity: Adding 2-digit numbers Complete this interactive activity to learn more about adding numbers using column addition and then put your knowledge to the test with a quiz.