This is a Web-base of 101 mathematics problems that are searchable by keyword or by categories. The site provides a bibliography of sources, and an explanation of the categories listed on the search page. Some of the areas of mathematics that can be searched are geometry, algebra, probability and statistics. Another category included is types of thinking which includes reasoning, process, and puzzle problems.
this website has activities you can use inclass or have students play with. it also has lessons, standards, and web links that are helpful to math teachers k-12 illustrate and teach math topics.