A simple lesson about simple interest: you simply multiply the principal, the interest rate (written as a DECIMAL), and the time. That is because the interest simply is a certain percentage OF the principal amount (so that's why we multiply the percentage and the interest rate), multiplied by the amount of time. So, the formula for simple interest, I = Prt, makes sense.
One thing to take note of is that sometimes the interest rate may be given as ANNUAL rate, whereas the time period is in months. In this case, you can either calculate the monthly interest rate, or convert the time period into years.
Basic percent word problems — video lesson
Math Mammoth Grade 7 curriculum (pre-algebra)
Math Mammoth TourConfused about the different options? Take a virtual email tour around Math Mammoth! You'll receive: An initial email to download your GIFT of over 400 free worksheets and sample pages from my books. Six other "TOURSTOP" emails that explain the important things and commonly asked questions concerning Math Mammoth curriculum. (Find out the differences between all these different-colored series!)This way, you'll have time to digest the information over one or two weeks, plus an opportunity to ask me personally about the curriculum. A monthly collection of math teaching tips & Math Mammoth updates (unsubscribe any time) We respect your email privacy.
Note: You will FIRST get an email that asks you to confirm your email address. If you cannot find this confirmation email, please check your SPAM/JUNK folder. |
"Mini" Math Teaching CourseThis is a little "virtual" 2-week course, where you will receive emails on important topics on teaching math, including:
- How to help a student who is behind You will also receive: A GIFT of over 400 free worksheets and sample pages from my books right in the very beginning.![]() We respect your email privacy.
Note: You will FIRST get an email that asks you to confirm your email address. If you cannot find this confirmation email, please check your SPAM/JUNK folder. |
Maria's Math TipsEnter your email to receive math teaching tips, resources, Math Mammoth news & sales, humor, and more! I tend to send out these tips about once monthly, near the beginning of the month, but occasionally you may hear from me twice per month (and sometimes less often). Peek at the previous tips here. You will also receive:
We respect your email privacy.
|