# Cockroach Slope

**Cube Fellow: **Casey Gregory**
Teacher Mentor: **Pamela Callahan

**10th /Honors Geometry**

Grade/Course:

Grade/Course:

**KY Standards:
**

MA-HS-5.1.5 Students will determine the slope and intercepts of a

linear function.

MA-HS-4.1.2 Students will construct data displays for data with no

more than two variables.

Kentucky Academic Expectation 1.6: Students use computers and other

types of technology to collect organize and communicate information and

ideas.

**Objectives:**

• The student will exercise their ability to quickly compute the slope

and y-intercept of a line.

• The student will visually be able to determine the difference between

a line with negative, positive, zero or undefined slope.

• The student will understand that when the y-intercept is zero, the

equation of a line is of the form y=mx where m is the slope.

• The student will understand that when the slope is zero, the equation

of the line is of the form y=b where b is the y-int.

• The student will demonstrate their capability of using a Java applet

via Internet Explorer.

**Resources/Materials needed:**

• One computer per student with internet access

• Data Collection Sheet (attached)

**Game Summary:**

The purpose of this game is to watch a cockroach crawling along a

line. The student should enter the slope (and/or y-intercept) as prompted,

then click Fire!. If they have entered the required information correctly, the

cockroach will be exterminated.

This is an excellent activity to give students practice with finding slope as it

breaks down the levels in logical steps. First the students compute only the

y-intercept. During the second level students compute only the slope. Then

each level gets successively harder: lines with positive slope, lines with

positive fractional slopes, lines with negative slopes, lines with negative

fractional slopes, all mixed together.

**Motivation**

Mrs. Callahan was having a hard time getting students interested in

slope. They had used slope in their previous math classes, and had not

mastered the concept. Many students were confused and discouraged about

learning (re-learning) the concept.

Mrs. Callahan asked me to come up with a fun, interactive way to get

students interested in slope. I found this Java applet on the web and

formulated an activity sheet to go along with it. I was interested, not only in

making sure that the students played the game, but also in seeing how long it

took them to compute each level. (That is why there is a space to record

how many cockroaches were exterminated.)

**Prior Knowledge**

Students are expected to have a solid understanding of what slopes,
y-intercepts,

equations in slope intercept form are and how to compute them.

The students we were working with had just finished a two-day lesson on the

above information and were ready to practice. This is not a lesson to use

before a student has been given the appropriate definitions and formulas as

the game does not explain in depth how to determine slope or y-intercept.

The game does give good hints, but they would be of little use for a student

who did not have the background information.

**Outline of Lesson**

I. This activity is to be done individually. I believe that group-work

would be quite disruptive, especially if the class is large.

II. Before going to the computer lab (perhaps even the class before)

the teacher should go through and explain the cockroach activity.

It would be best if the teacher could actually demonstrate how the

game is played. The instructions should be explained in advance

so that students know exactly what is expected of them. The

activity should take at least 50 minutes.

III. On the day of the activity the students should be
taken straight to

the computer.

IV. During the activity the teacher should circulate making sure that

the students are on task and not having any trouble doing what the

sheet asks of them.

V. The wrap-up is the most important part of the activity:

a. The teacher should go over the results with the student that day

if possible. The teacher should review the data sheets if there is

not time and then review the activity the following day.

b. The teacher should ask such questions as:

i. “What happens when the slope is zero?” (What does the

equation look like/what does the graph look like)

ii. “What happens when the y-intercept is zero?” (Does the

line go through the origin?/What does the equation look

like)

iii. “What is the slope of a horizontal/vertical line?”

iv. etc...

c. The teacher should give students a chance to share something

that they learned.

*Mrs. Callahan actually spent the day after the activity in class going

through the game where she projected it onto the screen in her classroom.

The students struggled with it in the computer lab, and she went through

several of the levels herself in front of the class discussing her thought

process.*

*Note: I highly suggest you try this activity before giving it to your

students. It takes a short time to get used to, and will make the classroom

activity go much more smoothly. If you have the capability to project the

computer screen to the class, it would be very helpful to walk them through

the first level and explain your thought process.*

**Something to think about: Many of the students were discouraged at first

with this activity because the cockroaches move fairly fast up and down the

line. They were worried that if they did not compute the slope fast enough

that they would lose a level. The game allows nearly 20 cockroaches to

accumulate on the line before abandoning the level. Even then, the student

will be able to play the level over. Just assure your students that they have

plenty of time to compute each step. The hints are often very helpful, as

they highlight the key coordinates on the axis.***

-Suggestion for follow up:

Several bell-ringers could be created for follow up on this activity. One idea

I would like to see is on an exam or quiz, a screen-shot of the game when

there are 10-12 cockroaches on the line (so that the line can be seen in a still

frame). The teacher could simply ask the equation of the line so that the

activity is not forgotten about later, and the students can have a little sense
of

enjoyment while taking the exam/quiz. (Teachers could even come up with

some other object to put on the line, such as pencils, etc.)

**Lesson Source**

I developed this activity and the data collection sheet based on the Java

applet at:

**Mode of Instruction**

This activity should follow a unit on slope. This is a good

supplemental activity before an exam. The mode of instruction is student

self-discovery on an individual basis. Each student is responsible for their

own work and learning. The teacher is only a facilitator and wrap-up leader.

**Date of Implementation/ Estimated Time
**

Tuesday, December 2, 2008/ 50 minutes

**Date Submitted to Algebra**

^{3}Tuesday, February 17, 2009

attachment: Cockroach Data Collection