Estimation

Overview

Estimation is a vague topic in most Math classes, regardless of the grade level. In most of the workbooks that I use with my sixth grade students throughout the school year, we see the word estimation in many of the questions. What we don't see however, is an explanation as to what estimation is, what it is used for, or how to use it. Too often estimation is thought of as merely a guess and not much more. Estimation is in fact not a guess, nor an educated guess, but rather an effective way of calculating an approximate answer to a question. Estimation is based on Math, not on a guess, educated or otherwise. There are several math concepts that students must be familiar with in order to effectively utilize estimation in the classroom including, place value, expanded notation, very round numbers, and order of magnitude. A familiarity with the powers of 10 would be beneficial as well. Since these concepts are ones that we teach in the sixth grade, I have incorporated teaching them into this unit.

At the beginning of each school year, I go through the same ritual with my Math students. I ask how many of them love Math. As a Math teacher, you probably already know where this is heading, but I'll tell you how it usually goes for me. If I get four confidently raised hands out of the 32 in the class, it is a lot. The next question I ask catches them by surprise. I ask how many of them hate Math. There are always the mischievous smiles on many faces, combined with a glance around the room to the other students looking for reinforcements before they commit to raising their hand. I tell them that yes, it is OK to answer the question honestly because it helps me know how I need to approach the class. Then my third question - Why do you hate Math? I usually get the same three answers each year; it's boring, I didn't like my teacher, or simply put, Math sucks! We can even thank Jimmy Buffett for writing a song of the same title, Math Sucks. By asking these questions, I get a good idea of the overall feel of the students' attitude towards the subject. My goal? That by the end of the year I can change their perception of Math and their preconceived notion that they cannot do well in it because they never have in the past. As teachers, if we can make the classroom environment lively and entertaining then we can hold their attention long enough to teach them Math and get them engaged in our lessons. We must also make our lessons as interesting as we can, which is why I chose the horseshoe crab (limulus polyphemus) as the focus for this unit.