More than 2,200 years ago, Eratosthenes, who was a Greek astronomer, geographer, and mathematician, used a simple proportion involving the distance between two ancient cities and measures of shadows cast in those cities during a summer solstice to estimate the circumference of Earth (Nicastro 2008, 25-28). Today, middle school students can use…

Having an answer to "When are we ever going to use this in real life?" is important to middle school mathematics teachers. The activity described in this article awakened sixth graders' understanding of how artists use mathematics. By exploring ratio and proportionality in different paintings, students realized the use of proportional…