# GSA Annual Meeting, November 5-8, 2001

Paper No. 0
Presentation Time: 9:15 AM

# IMPROVING THE QUANTITATIVE SKILLS OF PRE-SERVICE TEACHERS USING AN EARTH SCIENCE CONTEXT

RIGGS, Eric M., Department of Geological Sciences and CRMSE, San Diego State Univ, 5500 Campanile Dr, San Diego, CA 92182-1020 and KIMBROUGH, David L., San Diego State Univ, 5500 Campanile Dr, San Diego, CA 92182-1020, eriggs@geology.sdsu.edu

One of the most critical skills required by K-6 school teachers is a solid grasp of basic math. However, pre-service teachers often report math phobia and often avoid quantitative courses, potentially compromising their ability to teach math and science effectively. To improve the math skills of pre-service teachers, we developed curriculum units using geoscience topics as a concrete context for math ideas. We present data illustrating the successful ongoing evolution of an area and volume unit which precedes a unit on mass and density within the earth. This subject involves calculating the volumes of nested spherical shells (the internal layering of the earth). Our initial approach used lecture and written exercises on spherical shell volumes, assessed with isomorphic exam questions. Based on exam scores, we grouped students into three performance levels for data analysis. The results show that students at all performance levels were able to calculate the volume of the core using the spherical volume formula, but only the few high performing students demonstrated the conceptual understanding needed to use this formula appropriately for the other layers. We modified this unit to introduce students to progressively difficult problems, stressing the conceptual approach to the problems along with measurement, calculation, and basic algebra skills. Students were also expected to calculate volumes of complex physical objects and check their answers by direct measurement. The assessments were structured like the exercise, with added questions asking students to articulate their approach to the problems in words first, followed by calculations. The results show an overall increase in competency, with students at high and middle performance levels understanding the conceptual approach to the problems. The three performance levels differed largely by students at lower levels failing at calculation tasks earlier in a series of problems of increasing difficulty even when conceptual understanding was high. By using a concrete earth science context for this unit, we are able to enhance student conceptual understanding of quantitative problem solving and also decrease reported student math phobia. This unit also prepared the students better for understanding mass and density, and other proportional reasoning skills.