standard_description: Represent transformations in the plane using, e.g., transparencies and geometry software; describe transformations as functions that take points in the plane as inputs and give other points as outputs. Compare transformations that preserve distance and angle to those that do not (e.g., translation versus horizontal stretch).
problem_activity: Task
Materials
10-15 quart plastic bags of various counters (different numbers of counters in each bag)
A recording sheet for the activity with pictures of counters and lines for recording the total number of objects
A teacher completed recording sheet with the correct numbers written for each item
[IMG]
Action
The students choose a bag they have not counted. They are given the directions to count the items in the bag and record the number on the line next to the picture of the item in the bag.  The students will then check their answers against the teacher-prepared recording sheet.  If the activity is done in committee, the teacher should ask each student, “How many  (triangles) were in the bag?”  If the activity is done daily, the teacher should ask four or five different students, “How many  (triangles) were in the bag?”  The process is repeated until time runs out or all bags of stuff have been counted.


aligns: no