6th Grade Math Textbook, Progress

Line Graphs

9-9

Mr. Fleury, owner of Pizzas Unlimited, records

pizza sales for 6 days.

Day Mon. Tues. Wed. Thurs. Fri. Sat.

Pizzas Sold 100 90 80 60 40 30

The broken scale indicates that

part of the scale is missing.

Researchers conducted a survey and concluded

that of every 50 pizzas ordered, people will

request extra cheese on 9 of them.

Use a line graph to compare two

quantities, such as the number of pizzas

ordered and the number of pizzas with

extra cheese. As the number of pizzas

ordered increases, the number of pizzas

with extra cheese also increases.

From left to right, the line slopes upward.

Mon. Tues.Wed. Thurs. Fri. Sat.

110

100

90

80

70

60

50

40

30

0

Number of Pizzas

Day

Pizzas Sold

0 50 100 150 200 250

9

18

27

36

45

54

63

Extra Cheese Pizzas

Pizzas Ordered

Pizza Survey

Mr. Fleury displayed his sales in a line graph.

A line graph is used to show changes in data over time.

To make a line graph:


Draw horizontal and vertical axes on

grid paper. Label the axes.


Use the data from the table to choose

an appropriate scale (intervals of 10).


Start at 0 and label equal intervals

of the scale on the vertical axis.


Label the horizontal axis by day.


Graph the points on the grid.


Connect the points with line segments.


Write a title for the graph.

To determine a trend, look for a rise (the

data show an increase) or a fall (the data

show a decrease) in the line between

two points.

The number of pizzas sold decreased

each day.

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