math 5 two line graphs instructor: mrs. tew turner

Math 5Two Line Graphs

Instructor: Mrs. Tew Turner

In this lesson we will use two rules and generate two numerical patterns. We will

create line graphs to represent the pattern.

Math Warm-up

Write five fractions equivalent to ½.

Math Warm-up - ANSWER

Your answer may include: 2/4, 4/8, 8/16, 7/14, 9/18, 6/12, 10/20, etc.

In this lesson we will answer the question:

How can you use the data from twopatterns, and graph the ordered pairs on a coordinate plane?

Vocabulary Review coordinate plane- is a flat surface formed by two intersecting, perpendicular lines. Each of these lines is called an axis. x-axis- The horizontal line.

y-axis- The vertical line.

Vocabulary ReviewQuadrants-The x-axis and the y-axis divide the coordinate plane into four areas. These areas are called quadrants.

Ordered Pairs- Digits that indicate where a point is located on a coordinate grid. Ex: (3,2)

Connecting to Previous Learning

In the last lesson you learned how to create a line graph given a set of data, or an equation. In this lesson, you will use the same skills to create a double line graph with two sets of data.

Double Line Graph

A double line graph represents 2 rules creating 2 numerical patterns.

Let’s look at the example on the next slide.

Example double Line Graph:

Today, both Sam and Terri have no fish. They both go fishing each day. Sam catches 2 fish each day. Terri catches 4 fish each day. How many fish do they have after each of the five days? Make a graph of the number of fish. Interpret the graph.

Data for double line graph

The ordered pairs taken from the table for Sam:(0,0) (1,2) (2,4) (3,6) (4,8) (5,10)The ordered pairs taken from the table for Terri:(0,0) (1,4) (2,8) (3,12) (4,16) (5,20)

This data can be shown on a double line plot because the rates are constant for both Sam and Terri, showing a straight line.

Ex

Double Line Graph:

Interpreting the Graph:

The graph shows us the relationship between Terri’s and Sam’s fish catches. The graph shows that Terri always has more fish than Sam. Terri’s fish increases at a higher rate since he catches 4 fish every day. Sam only catches 2 fish every day, so his number of fish increases at a smaller rate than Terri’s does.

Interpreting the Relationship:

The two lines will never intersect; there will not be a day in which boys have the same total of fish, explain the relationship between the number of days that has passed and the number of fish a boy has (2n or 4n, n being the number of days).

Interpreting the Relationship:

The lines become further apart as each day passes. This is because Terri catches fish at a higher rate than Sam.

Let’s look at the relationship between the points on the graphs.

Ex

Double Line Graph:

Document Camera

Get your notebook

and pencil ready.

Make sure you

have the Lesson #

and date on your

page.

In your Math NotebookIndependent Practice

Juna makes $10 each week doing chores for the community. Raya makes $15 each week helping an elderly neighbor. How much money do they each have after five weeks? Make a graph of the money they earned. Interpret the graph to tell the relationship between the data.

Data can be shown on a double line plot because the rates are constant

for both sets of data, showing a straight line. Basically, a double line

graph consists of two linear equations that are being plotted on the same graph. This is usually so the two graphs can be compared.

Lesson Review

Quick CheckIn your Math Notebook

1. What is the purpose of a Double Line Graph?

Quick Check - ANSWERIn your Math Notebook

1. What is the purpose of a Double Line Graph?

The purpose of a Double Line Graph is to compare two sets of data.

Quick CheckIn your Math Notebook

2. Lars walks 10 miles each week to go to and from school. Noran walks 15 miles each week to go to and from school. How many miles do they each walk after 5 weeks? Make a graph of the distance they walk. Interpret the graph to tell the relationship between the data.

Today you learned how to graph two sets of data and interpret the graph.

Good Work with this

lesson.