Applied Science - Science and Math (3A) Pre Lab
 OBJECTIVES: Comparing objects mathematically. Measuring objects. VOCABULARY: geometry mathematics metric MATERIALS:  metric rulers  worksheet Student measure length and width of two-dimensional objects.
 BACKGROUND: Students should have an understanding of basic arithmetic skills by the third grade.  However, much of their understanding of arithmetic is how to manipulate numbers and find answers.  Many students find this boring and tedious and develop a dislike for mathematics.  Mathematics is a diverse topic that has fascinated humans for a long time.  Importantly, mathematics is useful to scientists, business, painters, builders, and economist to name of few.      Math provides a greater ability to describe objects.  If a student has a good knowledge of geometry, they are able to describe what they see.  Geometry can be divided into linear geometry which describes 1 or 2 dimensional objects, and solid geometry which describes three-dimensional objects.  Many subjects in science require this qualitative ability to describe things. Without the ability to measure or see shapes, a student will not be able to further their investigations.    In this activity, students describe and measure the length of 2 dimensional shapes.  In the lab, students will be asked to describe different objects.  It is difficult for students to describe shapes and to estimate length without prior practice.  Students will use the worksheet to help them develop measurement skills and shape recognition. PROCEDURE: Discuss the differences between 2 dimensional and 3 dimensional objects.  Some shapes such as diamonds or hearts can be both 3 dimensional or 2 dimensional.  Ask the students to describe shapes in the room and estimate linear measurements.    Describe length of an object as the longest measurement, width as the shortest.  It doesn't matter which way you turn the object, the measurements are constant.  There are some exceptions to this, especially with objects you cannot move.  Vertical blinds for a window are one exception; the width is always parallel to the floor and the length is perpendicular to the floor.    Distribute the worksheets and metric rulers to the students. Tell the students that they will be measuring objects using the metric system.  They will measure the objects in centimeters.  Using centimeters is  much easier to measure objects  and helps students understand decimals and percentage.  For instance, if an object is 1 cm and 5 mm in length, the student writes 1.5 cm.  1 is the number of cm (before the decimal) and 5 is the number of mm (after the decimal).  There is no conversion in metric because it is base 10 already.  Make sure the students know the difference between cm and mm "ticks" on the ruler.  Do not make student “convert” from the English to metric.  They need to get an feeling for the metric with a conversion factor.      Model how to do the first object.  On the board write down the width, length, and shape of the object.  Work this problem with the students.   Show the students where to record their answers.    Allow students time to complete the worksheet on their own or with a partner.  Monitor them as they work.     After the students have finished measuring all the objects, orally review their results.  Give them the names of the shapes if they did not get them correct.  Remember there is  margin of error when measuring, so allow them a little leeway.