While the study of Matter begins with an exploration of objects common to students, the topic quickly becomes  more complex (especially for younger students) as they:

• discover the similarities and differences in the properties of materials
• determine the three states of matter: solid, liquid, and gas
• see how matter can be changed through mixing, dissolving, heating, cooling, or freezing.

For younger students, clarifying the concepts of Matter is essential because:

• while everyone has experience with Matter in a variety of forms, many students in Grades 1-3 have unclear and even erroneous ideas about Matter
• the concept of mass develops slowly. Younger students often think that mass is connected to density or volume
• students have difficulty understanding that gases contain weight or mass
• when materials are dissolved students often think that the mass has changed
• students are often confused about the difference between weight and density. They need to correctly understand these concepts in order to comprehend conservation of matter.
  

Now the teaching resource handbook, Doing Science: Grades 1-3: Matter, designed by expert science educators gives teachers:

• practical step-by-step teaching directions for this challenging and complex topic
• teacher background information on each aspect of Matter so the topic can be taught with confidence
• hands-on activities that will both interest and challenge students, while teaching them essential characteristics of Matter
• equipment and materials lists so teachers can be fully prepared for the lessons
• descriptions of student learning centers
• assessment charts to quickly measure and report student achievement.