The sites mentioned below have information you can use to review, or test your understanding of decimals. Here is a table that gives the decimal equivalent of many common fractions. This site gives instructions on converting decimals to fractions. It has sample problems you can try. This page has a review of decimals along with practice problems.
Answers appear at the bottom of the page.
This site has an interesting extension on converting repeating decimals to fractions. The calculators in Chapter 1 will also work with decimals. Using the following sites you can get the exchange rate between major currencies. This converter had more currencies listed than any other I found. Find the price of an expensive pen in the catalog.