Connect students directly to the concept in a personal way. Capture students' attention by initiating a group problem-solving activity before delivery of instruction. Begin with a situation that is familiar to students and builds on what they already know. Construct a learning experience that allows diverse and personal student responses. Facilitate the work of cooperative teams of students.

Small group estimation problem.

Objective: To gain an appreciation for the importance of being able to estimate the number of particles in a sample of a substance.

Activity: The teacher labels and displays jars containing 150 of each of the following: marbles, paper clips, grains of rice, pennies, BB's, iron filings, etc. Additional jars have samples of elements and compounds such as zinc, water, and magnesium, or multiple units of 2 to 3 connected items. Students work in small groups. Each group is given a different jar and must follow the appropriate directions from the following: 1. Estimate the number of particles in your sample, or 2. Estimate the number of atoms in your sample, or 3. Estimate the number of molecules in your sample.

Assessment: Involvement of students in activity and contributions to the efforts of their group.