Smithsonian Institution
Smithsonian Learning Lab: Prehistoric Climate Change and Why It Matters Today
Introduce students to environmental issues by studying a time of rapid global warming that occurred 50 million years ago. Lessons, video segments and interactive activities will engage students as they learn about average annual...
Calculator Soup
Calculator Soup: Odds Probability Calculator
Convert stated odds to a decimal value of probability and a percentage value of winning and losing. This calculator will convert "odds for winning" an event or "odds against winning" an event into percentage chances of both winning and...
Calculator Soup
Calculator Soup: Fraction to Percent Calculator
Convert a fraction to a percent. Convert proper and improper fractions to percentages. This calculator shows the steps and work to convert a fraction to a percentage number.
Calculator Soup
Calculator Soup: Tip Calculator
Calculate a tip or gratuity and get the total amount to pay. Enter your meal or dinner cost along with the tip percentage. If you are splitting the cost at a restaurant among several people you can divide by the number of people to get...
Science Struck
Science Struck: A Simple Guide on How to Calculate Theoretical Yield
Explains vocabulary used when talking about the yield of a chemical reaction and models how to calculate the theoretical and the percentage yield in an example problem.
Calculator Soup
Calculator Soup: Mixed Number to Percent Calculator
Convert mixed numbers or mixed fractions to percents. The mixed number to percentage calculator finds the decimal equivalent by finding the decimal value of the fraction, adding the decimal to the whole number part of the mixed number,...
Math Drills
Math Drills: Percents Worksheets
Download these worksheets to sharpen your percent calculation skills. Sheets focus on the percentage of a number, percentage rate, and percentage increase/decrease.
Council for Economic Education
Econ Ed Link: Be All You Can Be for Minimum Wage? (Student Page)
This lesson ask students to calculate the percentage change in military strength over the last two decades, hypothesize economic (and non-economic) explanations for these changes, test hypothetical explanations by reading an economic...
Khan Academy
Khan Academy: What Is an Apr by Better Money Habits
You may have seen the term APR, or annual percentage rate, used in reference to everything from mortgages and auto loans to credit cards. In this piece, we look at credit card APRs which you've probably seen listed on your monthly...
Help Algebra
Help algebra.com: Percents
Converting percents to and from decimals and fractions is demonstrated in detailed examples. Once the concept is understood, you can use it to solve equations that contain percents.