[[alternative]]Evaluation and Teaching of Students' Volume Concept from 4th to 9th Grades

[[abstract]]The acquisition of conservation concept of volume is the first step into formal operational stage. Students with this concept have the reasoning ability to learn abstract concepts, such as density, mole and chemical reations concepts. This study was to investigate the development of students' volume concept, to explore the effect of acquisition of volume concept through appropriate teaching activities, to find the relationships between students' development of volume concept and achievement of density concept, and to probe into whether this instruction could improve student conceptual change of density. The volume concept included volume conservation concept and conservation of displacement volume. Tortally 1406 students from grade 4th to 9th were involved in this paper.The instruments used in this research were as following：(1)diagnostic test of volume concept , (2)diagnostic test of cognitive development , (3)teaching activities of volume concept , and (4) post-test . The main findings of this paper were︰（1）The percentage of students with correct volume concept increased from grade 4th to 9th gradually. The proportion was increasing largely at the grade 8th. For students without volume concept, the percentage of students who acquired volume concept also increased with grade.(2）The teaching activities based on learnimg cycle could promote the acquisition of volume conservation concept and conservation of displacement volume . (3)For students without volume concept, if they had correct weight concept, they would acquire better volume concept through teaching activities . (4）There was a significant correlation statistically between the development of volume concept and the achievement of density concept. The teaching activities of volume concept could help some students acquire correct density concept.