http://www.janbrett.com/piggybacks/rounding.htm Seashell Rounding Math:This interactive math page for elementary students lets them practice rounding skills. They must round numbers on the seashells to the nearest ten, and collect sand dollars for each correct answer.

http://www.numeracyhelper.com/pvslider/ Place Value Holder Tool - what happens to a number when it is divided or multiplied by 10, (100 or 1000)? This great tool shows you!!

http://home.mindspring.com/~mjg2/ethalt.html Ethnomathematics Webhunt:... students explore math in cultures across the ages, from African games, to Mayan calendars, to the first use of zero and negative numbers--fascinating material.

http://www.funbrain.com/ofm/index.html click on the squares starting at the lowest number and continuing to the highest - you can choose the level of difficulty of this game