Estimation

Introduction

Place value: the value assigned to each place in a numeral, depending on the base of the number system. This is not exactly a definition that is accessible and useful to a primary teacher! Of course we need to teach this essential concept to our math students as the foundation of our notation system and maybe more importantly as a foundation of their future mathematics study. These young students are cognitively ready to learn, understand and use purposefully the idea of place value. Through this unit primary teachers themselves will gain a more complete understanding of place value as a real life skill and subsequently use the strategies and lessons for their students to have the same result. The key ideas of this unit are adapted from the Singapore mathematics program, a consistently successful approach to teaching elementary school students.

As a first grade teacher in a self-contained classroom in New Haven, my class is 26 six and seven year olds with an occasional eight year old. Our neighborhood/ magnet setting is a rewarding environment, with students coming to school each day from a variety of home circumstances and with differences in academic levels. As a result of these variables, the children have differing levels of background knowledge and life experiences. The classroom is a mixture of varied ethnicities, economic strata and social and emotional strengths and weaknesses.

During the last two years our school district has been piloting new elementary mathematics curricula. My school in particular has worked with two different mathematics programs, both in their early trial years. The first year was Math Expressions, published by Houghton Mifflin and developed by The Children's Math Worlds Research Project. The second, which is this current year, is ThinkMath, published by Harcourt and developed by Education Development Center, Inc through the National Science Foundation. These two piloted programs each present different math foundation strategies. It is difficult to know how the students will perform in future grades having had these two separate approaches during their first and second grades. We are continuing with ThinkMath for the coming year which will provide some consistency. By incorporating this unit into our mathematics curriculum, I hope to effectively teach the students the concept of place value, certainly an essential skill no matter what publisher we finally identify for the district!