Short Range Lesson Plan 4
Title of Lesson: Direct Variation
Subject: Algebra I Mastery
Grade Level: 9th
Teacher: Ms. Shuey
Objectives:

Students should be able to connect the diameter and circumference of the objects to direct
variation.

Students should be able to determine whether the equation for circumference is a direct
variation equation.

Students should be able to complete the activity in the given time.
SCSCE Standards Addressed:

The state standards that apply are in elementary algebra under the third standard: The
student will demonstrate through the mathematical processes an understanding of
relationships and functions.

EA-3.6 Classify a variation as either direct or inverse.
NCTM National Curriculum Standards:

One national standard that apply to this unit are under problem solving, specifically
solving problems that arise in mathematics and other contexts as well as apply and adapt
a variety of strategies to solve problems. The other national standard in algebra that
applies to this unit is to represent and analyze mathematical situations and structures
using algebraic symbols.

Another national standard that applies here is under the number and operations sixth
through eighth grade standards. It states that students should be able to understand and
use ratios and proportions to represent quantitative relationships. Students have to
understand ratios and proportions in order to understand direct variation.

Another national standard that applies in in the high school algebra category. It states that
students should be able to understand relations and functions.
Prerequisites:

Students should know what the equation for direct proportion is.

Students should know how to measure circumference and diameter of a circular object.

Students should know how to figure out if an equation is a direct variation equation.
Materials and Preparation:

9 rulers

9 bundles of string

At least 9 circular objects around the room

Activity worksheet for each the of the 9 groups(see attached)

Smartboard- the worksheet for the activity will be projected on the board and groups will
be chosen using this
Procedures:

Introductory Activity: Once the students are settled, we will have a discussion about the
direct variation lesson they had previously. I will first ask what the general equation for
direct variation equation is. The students will answer y = kx. After that the students will
be asked what k is called. They should answer that k is the constant of variation.

Main Activity: Direct Variation Activity
o After this discussion, I will then introduce the day’s activity. I will first start by
saying that this is an activity that is about direct variation. Then I will ask them to
look at the worksheet that they were given. I will go over the instructions.
o I will say that the students are going to be put into groups of three using the
smartboard group chooser. Then I will say that there are several objects around
the room at that are circles and that each group will need to measure the
circumference and diameter of each of the 5 objects that they choose to measure.
To measure the circumference each measurer will need to unravel the string and
place it going around the outside of the circular object. Then mark your
circumference on the string with either a pen mark or just by holding your finger
in the correct place. Then the measurer will unroll the string from around the
object and place it on the ruler they have to see the length of the circumference.
The measurer will do a similar thing for the diameter. The measurer will just
need to place the string in a straight line across the middle of the circular object
and mark where the object ends and begins on the string. The measurer will then
need to place the string on the ruler to determine the length of the diameter.
o After I explain all of this, I will explain that the recorder in each group will write
down all the measurements that the measurer takes and that the calculator in each
group will use the calculator to determine the answer for the circumference over
the diameter for each object measured.
o I will then explain that after the table has been filled out on the worksheet, they
are to move on to the questions at the bottom. The recorder does not have to be
the one to write these answers down. Everyone should be helping to answer these
questions and anyone can write the answers down.
o After these directions are explained to the class, I will pull up the smartboard
group chooser and do that until we have 9 groups of three randomly chosen. Once
the groups are chosen, I will allow the groups to get up and move and begin
measuring the five circular objects that they need to.
o I expect this project to take the whole class period, so the students closing activity
will be to complete the questions at the end of the worksheet.
o The students will turn in one worksheet per group to me by the end of class.
Assessment:

The assessment for this lesson will be the completion and correctness of the worksheet
that goes along with the activity. The questions at the bottom are the most important to
me. If they can get those questions correct, I know that they understood the activity and
understand direct variation.
Adaptations:

I will include all abilities and paces in the lesson by giving the students a chance to ask
questions when working on this activity.

In addition, if struggling students would have a harder time being the measurer of the
group they always have other options. They could be the recorder or calculator. It allows
the students to have the freedom to choose what job fits them best.
Follow Up Lesson:

The next lesson after this one would be moving into inverse variation and then we would
be at the end of the material for the test. So we would have a review day and test
sometime that week.