Middle Grades Mathematics Project is a series of teacher resource books with unique teaching guides and blackline masters designed to help teachers develop students' problem-solving skills via activity-oriented mathematics. The materials have been excellent resources for both pre-service and practicing teachers in creating curriculum replacement units, and are appropriate for a broad range of grade levels and student abilities. The series includes five books, all published by Addison-Wesley Publishing Company:
Mouse and Elephant: Measuring Growth, by Shroyer and Fitzgerald, discusses area, perimeter, surface area, and volume by considering the relative sizes of a mouse and an elephant.
Factors and Multiples, by Fitzgerald, Winter, Lappan, and Phillips, uses games and problem situations to examine the concepts of primes, factors, divisors, multiples, common factor, common multiple, relatively prime, and composite.
Similarity and Equivalent Fractions, by Lappan, Fitzgerald, Winter, and Phillips, develops and understanding of similar figures and equivalent fractions through indirect measurement, scale models, and the nature of growth.
Spatial Visualization, by Winter, Lappan, Phillips, and Fitzgerald, explores representing three-dimensional objects in two-dimensional drawings then, conversely, constructing (with cubes) three-dimensional objects from their two-dimensional representations.
Probability, by Phillips, Lappan, Winter, and Fitzgerald, introduces the concepts of probability--fair games, equally-likely outcomes, expected value, simulations, Pascal's Triangle, and the binomial distribution.