Content Area: Math

 

Index: 4.2D Grade 12 CPI 2

 

Standard: 4.2 - Geometry and Measurement

 

Strand: D - Units of Measurement

 

Cumulative Progress Indicator: 2 -  The student will choose appropriate tools and techniques to achieve the specified degree of precision and error needed in a situation

·        Degree of accuracy of a given measurement tool

·        Finding the interval in which a computed measure (e.g., area or volume) lies, given the degree of precision of linear measurements

 

Grade: 12

 

Sample Activities

 

·        Students use significant digits appropriately in measuring large distances, such as the distance from one school to another, from one city to another, and from one planet to another.

 

·        Students find the distance between two cities by adding the numbers given on a road map for the segments of the trip, by measuring the segments and using the mileage scale, and by referring to a published mileage table. They explain the different results by referring to the degrees of prevision of the different measurements.

 

·        In making a scale drawing of a house, students discuss the degree of accuracy of their measurements.

 

·        Students read and discuss the photographs in Powers of Ten by Phillip and Phylis Morrison and the office of Charles and Ray Eames, and view the associated videotape. This well known book takes the reader on a trip through perspectives representing forty two powers of ten, from the broadest view of the universe to the closest view of the nucleus of an atom. The measurement units used and the progression from one to another highlight the range and power of our system of measurement.

 

·        Students use computer drawing and measuring utilities to discover geometric concepts. They also discuss the limitations of such a program. For example, a program may give 14.7 for the length of the base of a triangle and 7.3 for its midline (the segment joining the midpoints of the other two sides); however, because of the program's measurement limitations, its answer for the length of the midline may not be exactly half the length of the base, as is the case in reality.

 

·        Students determine what kind of measuring instrument needs to be used to measure ingredients for pain-relievers, for cough syrup, for a cake, and for a stew. They bring to class a variety of empty bottles and packages and note how the ingredients are measured: What does 325 mg (of acetaminophen) mean, or one fluid ounce (of cough syrup) as opposed to 1/4 cup of oil (for a cake). They discuss the accuracy, error, and tolerance of each measurement.