K-8 Preservice Mathematics Teachers\u27 Application of Geometric Sequence in the Context of Compound Interest

Geometric Sequence is a number sequence in which the ratio of every pair of successive terms is constant. The constant ratio is called the common ratio. For example, the common ratio of the sequence 1, 3, 9, 27 is 3. The concept of the Geometric Sequence is applied widely in everyday life, including in finance and accounting. This concept also plays an important role in teacher education, as learning of sequences lays a foundation for learning of functions. However, K-8 preservice mathematics teachers (PMTs) often are challenged by real world applications of sequence. The purpose of this study is to include one of the most commonly applied mathematical models in finance and accounting, compound interest, in the task design of a mathematics content course for PMTs and examine the potential effectiveness of such instructional design. The free online interactive tool GeoGebra is also incorporated in the task design to help establish an active and equal learning environment. The data set includes PMTs’ problem solving results before and after the implementation of the designed tasks. PMTs’ successes, misconceptions, and breakthroughs will be unpacked through qualitative data analysis of their work on the tasks. Currently the data collection is ongoing