B1: I can calculate simple interest on a bank account.

The formula for simple interest: I = P x R x T Interest Principal Rate Time

Annual Interest Rate - The percent of the principal that you earn as interest based on one year.

Time is not always exact years so we have to write fractions of a year or decimals. All decimals should be written to seven place values. Do not round. Let’s try some!

6 months = 9 months = 15 days = 21 days = 87 days =

Example 1 : Principal: $700 Annual interest rate: 3 % What is the interest after 3 months? I = P x R x T P = 700 R=.03 T = 3/12 =.25 So, I = 700 x.03 x.25 = $5.25

Example 2: Colleen O’Rourke’s savings account : $4900 deposit at 4.25% annual interest rate for 6 months. Find the interest. I = P x R x T P = 4900 R =.0425 T = 6/12 =.5 I = 4900 x.0425 x.5 I = $104.13

B1: I can calculate the simple interest on a bank account. P. 206 #1-4, #10-13