The multiplication principle (MP) is a fundamental aspect of combinatorial enumeration, serving as an effective tool for solving counting problems and underlying many key combinatorial formulas. In this study, we used guided reinvention to investigate 2 undergraduate students' reasoning about the MP, and we sought to answer the following research…

Specially designed materials were used for teaching trigonometric ratios to 131 ninth- and tenth-grade students, one group using calculators and one not. Results on achievement were mixed. (MP)

This study compares three methods of introducing two-digit numeration. It is concluded that teachers should build on the preschool exposure children have in counting past ten, rather than have children begin by counting out groups of tens and ones and only later in the process use the normal number names. (MN)

Studied were the misconceptions that preservice elementary teachers have about multiplication and division. Results indicated that they are influenced by the same primitive models as students; the most common errors made by both groups are quite similar. (MNS)

A study compared the performance of two groups of university students. One group (n=40) was taught calculus using a computer algebra system whereas the other (n=41) used paper-and-pencil computations. The computer group scored significantly higher than their counterparts on both a conceptual knowledge test and a calculus computational exam. (JJK)

Report provides new data concerning children's accuracy as measured by previous studies and clarifies progress of first graders during entire year on difficult single-digit addition and subtraction problems. Discussion focuses on advantages of an adding on interpretation of subtraction and the importance of emphasizing conceptual understanding…

Investigates the development of concepts and processes associated with computational estimation. Twelve students at each of grades three, five, seven, and nine were interviewed. The older children understood better than the younger children what was asked but were uncomfortable with estimation processes and outcomes. (Author/YP)