Constant of Proportionality
TEACHERS:Mr. Nate Roberts / SUBJECT:
7th grade Math
STANDARD:
a. 7.RP.2b Explain what a point (x, y) on the graph of a proportional relationship means in terms of the situation, with special attention to the points (0, 0) and (1, r) where r is the unit rate.
OBJECTIVE (EXPLICIT):
· Identify the constant of proportionality for a proportional relationship.
EVIDENCE OF MASTERY (MEASURABLE):
SUB-OBJECTIVES, SWBAT (SEQUENCED FROM BASIC TO COMPLEX):
KEY VOCABULARY:
X,Y Coordinate Graph, unit rate, proportional / MATERIALS: XY Coordinate Pegboard
ENGAGE (MAKE CONTENT AND LEARNING RELEVANT TO REAL LIFE AND CONNECT TO STUDENT INTEREST)
BEFORE / TEACHER WILL: Introduce the following problem: For every 2 days in a week Sue saves $3. In 10 days, she saves 15 dollars. Is the the number of dollars Sue saves a proportional relationship?
Teacher Says: Lets demonstrate a proportional relationship by plotting the fractional relationships of 2/4 = 6/12 as ordered pairs (2,4) and (6,12). Orginating from (0,0) connect the 2 ordered pairs ordered pairs using the pegboard bands.
Techer Says: What would be another point in the graph? What shape does it make? (line) / STUDENT WILL: Think, Pair, Share the following questions: 1) What does it mean to be a proportional relationship? 2) What does a proportional relationship like like?
TSW: Using the XY Coordinate pegboard, graph the points (2,4) and (6,12).
Students Say: (4,8); A straight line
CO-TEACHING STRATEGY IF APPLICABLE
DURING / TEACHER WILL: Teacher says: Try to make another proportion with your partner.
With your partner graph 2/3 = 6/9 as an ordered pair.
Techer Says: What would be another point in the graph? What shape does it make? (line)
Teacher Says: Discuss what you found with your parter. / STUDENT WILL: Graph the ordered pair, then graph a 3rd point (ie. 4/6). Repeat for more porportions.
CO-TEACHING STRATEGY IF APPLICABLE
AFTER / TEACHER WILL: Pull class back together.
Teacher Says: OK what did you find? (they all create a straight line)
Teacher says: Is there a point all the graphs shared in common? (0,0)
Teacher says: Lets go back to the original problem and determine whether or not it is proportional.
Assessment: Have students complete journal in 15 words or less what does it mean to have a proportional relationship in terms of a situation. / STUDENT WILL:
Discuss/Share observations with class.
Students reply with (0,0).
Work indivdually to graph the original problem to discover that yes it is proportional.
Share journal entries with class or could be used as ticket out the door.
CO-TEACHING STRATEGY IF APPLICABLE