Significant Figures Review

Practice 0.0546 298.206 102000 0.003145 7847000

Round each number to four significant figures 84,791 38.5432 256.75 4.9356

Representing Data

It is sooooo important to communicate your results in science!

“A picture is worth a thousand words” Graph Visual display of data “A picture is worth a thousand words”

Why use graphs? Isn’t it a lot of extra work? What’s the point?

Graphing Experiment I will ask the entire class 3 questions on some information. All the information will be right up front for all of you to see while I ask the questions. As soon as you have the answer, raise your hand.

Six boys and six girls were surveyed on four different activities Six boys and six girls were surveyed on four different activities. They responded if they liked those activities or not. These are the results: Four out of the six girls said they liked to read. Two out of the six boys said they liked to read. Three out of the six girls said they liked to play video games. Six out of the six boys said they liked to play video games. Five out of the six girls said they liked to talk on the phone. Three out of the six boys said they liked to talk on the phone. Four out of the six girls said they liked to ride bikes. Five out of the six boys said they liked to ride bikes.

Questions: How many girls like to ride bikes? How many more girls like to read than boys? Which activity has close to the same amount of boys and girls interested in it?

Now let’s try it with a graph

Questions: How many boys like to talk on the phone? How many more boys like to play video games than girls? Which activity do girls like the most?

The results … Why use graphs? Easier to understand information Fast, clear and to the point Easier to see patterns and trends Which was easier?

Natural Gas Bill

Different Types of Graphs

Bar Graph Compares how a quantity varies across categories

Bar Graph We want to compare the total revenues of five different companies.

Line Graph Shows how something changes over time

Line Graph We want to compare populations of pandas over the past seven years

Stocks

Circle Graph (pie chart) Represents parts of a whole, percentages

Circle Graph 32% of Americans, 12% of Lithuanians, 21% of Germans, 27% of Spaniards, and 8% of others have gained more than 30 pounds in the past four years.

Test Scores 7% 18% 22% 18% 35%

Activities enjoyed by kids Reading Graphs 1st – Read the title 2nd – Read the x axis (independent variable) 3rd – Read the y axis (dependent variable) Activities enjoyed by kids

In an 8th grade class, 20% of the students are in band, 30% are in orchestra, and 90% are in choir. Which bar graph best represents this data? #1 #3 #2 #4

The enrollments made in elementary schools and high schools from 1994 through 1998 is given in a double bar graph. Which year has the maximum difference between enrollments of high schools and elementary schools? a. 1995 b. 1994 c. 1996 d. 1997

The line graph below represents the top wind speeds of Hurricane Gordon in 1999. Between which two days did the maximum wind speed increase the most?

The following table lists the population of Alaska from 1900–2000 The following table lists the population of Alaska from 1900–2000. What type of graph would best represent this data.