Developing Number Sense: An Intervention Study in Grade 7

Few students exhibit number sense when solving arithmetic problems in school. This study examined the effects of an intervention in the instruction of seventh-grade students for the purpose of developing number sense. Students were taught by the classroom teacher from experimental units on number magnitude, mental computation, and computational estimation. Instruction was designed to provide rich opportunities for exploring numbers, number relationships, and number operations and to discover rules and invent algorithms. Written measures and interviews before instruction, immediately after instruction, and several months later revealed that after instruction students were more likely to elect to use strategies that reflected number sense and that this was a long-term change. It appeared to the investigators that the students reorganized and used existing knowledge rather than acquiring new knowledge structures.