• AAA Math
As part of the AAA Math website, this link provides introductions and practice with ratios. Students can interactively practices skills relating to ratios.

• Fibonacci numbers
This website contains a detailed amount of information on Fibonacci numbers and the Golden Section, which could be used to demonstrate ratio concepts. It provides links as to how these concepts relate to nature and also provides opportunities for the user to practice ratio calculations.

• Fish Simulation Applet I
A collection of two colors of fish is to be placed into three ponds to create specified ratios within each pond. Students should find out if there is more than one solution and then make up similar problems for their classmates.

• Learning About Length, Area, Volume, Surface Area of Similar Objects
A two-part exploration complete with extensive teacher notes. The applets compare two rectangles or two prisms showing ratios of measures in both numeric and graphical form.

• Math Forum
Part of the Math Forum website, this link takes teachers directly to links of elementary activities for teaching ratio and proportion in elementary school. Many of the ideas are set up in a problem of the day format and even include samples of some student responses.

• Ratio concepts
This site is an excellent resource for students to review and practice ratio concepts. This main page can take students to three links, including an overview of ratios, practice with ratios, or how ratios relate to music. Parts of the site are interactive for students to practice problems.

• Ratio math lessons
A web page that offers excellent math lessons on ratios, proportional reasoning problems, and percentages.

• Understanding Ratios of Inscribed Figures
A nice geometry/measurement link to ratios. The user explores the ratio of figures inscribed in polygons formed by joining midpoints of sides. These points can also be adjusted. The supporting lesson and activity suggestions are quite good.