Algebra Balance Use this virtual manipulative to help you understand how to balance equations. Holt Mathematics, Course 1 This is the homepage for our textbook series. This site provides lots of useful tips and lessons. Math Circus! Is it fair? Try to figure out if the game described here is fair or not! E-Lab probablility experiment Virtual Manipulatives This site has a number of virtual "math manipulatives" to assist students in gaining a visual understanding of math concepts. Most of our work will involve the Grades 6-8 skills section.