Y

UNIT 4

USING VISUAL AIDS

LEARNING OUTCOMESAt the end of the unit, students should be able to:

identify visual aids and how are they used

read and interpret data presented in graphs

apply the data to find solutions

Introduction

ou have probably heard the saying "A picture is worth a thousand words." When you look at an image, your brain interprets it in an instant, while it might take you five minutes to read a page of dense text. Images and other visual aids are efficient ways to organize a lot of information in a

small space. Just think how much easier it is to look at a map of your city than to read a paragraph

explaining where all the roads are located. When we were young, most of our books had pictures on every page. As a child we need illustrations to help us understand the text. As we got older, our books are not always illustrated, but writers still use images and diagrams to help the reader visualize the information. Some of the most common visual aids are maps, illustrations, tables, time lines, and diagrams.

LEARNING POINTS

ILLUSTRATIONS

An illustration might be a photograph or a drawing. It could be simple, complicated or realistic. It might represent information, strengthen an argument, or tell a joke. A comic is a self-contained illustration with no accompanying text. Other illustrations are linked to written content.

When you come across an illustration in a book or on a text, there are a few things to check:

Context: If the illustration has an accompanying article or story, it is a good idea if you read that

first. Title: This is usually an easy clue to the main idea of the illustration.

Caption: This can provide an important explanation of what the illustration shows or what idea

the illustration is helping to prove.

Figure number: Books or articles that have more than one illustration often number the images to help

us as the readers to identify them. Illustrations might be numbered with whole numbers (1, 2, 3, and so

forth). They might also be numbered by chapter; the third picture in Chapter 4 could be called 4.3, 4-3,

or 4c. When you read a book or article that includes illustrations, check to see how the illustrations are

identified; then you'll be able to match the illustration to the related content in the text. This is

especially important when the illustrations are on a different page than the related text.

Labels: Within the illustration there might be words or symbols. These labels explain the parts of

the illustration and help the reader understand its meaning.

TABLES

A table is an organized grid of words or symbols. The information is arranged in columns and rows. Tables are an efficient way for writers to show lots of numbers or percentages that would be confusing in sentence form. A table usually has labels across the top, or the side, or both.

How to interpret figures/tables

S te p 1 (De scribe )

First determine how the figure/table is set up. This is the part that everyone would agree about and is not a

matter of interpretation. What are units on the axes (for a figure) or heading of the columns (for a

table)? Make sure you understand what these units mean. Pay attention to the symbols on a figure, the

differences between dotted and solid lines, and so on. Now look at the pattern in the data. For a figure

with lines, wha t is their pattern? For instance, do they increase linearly and then level off? In a table

do the numbers increase across the column? Pay attention to detail; that may be important. At this point

you should have a

pretty good idea of the question addressed by the data set and the experimental design — how it was

carried out.

S te p Two (In te rpret )

Now you are ready to interpret the data. What conclusions can you draw from the pattern that you have

described? What do these results tell you about the phenomenon being studied? How do they fit into

the larger picture of ecological thinking? Interpretations may well differ from person to person; this is to

be expected and makes discussions about data sets all the more interesting!

Before you look at the table, read the labels to see what is being measured and what units are used. You see tables on the back of every cereal box and food packets—nutrition labels are a type of table. Here's an

example of a nutrition table for potato chips.

Nutrition Facts

Amount per serving % value

Calories 140 7

Fat 7g 11

Cholesterol 0

Sodium 160mg 6

Carbohydrate 17g 6

Fiber 1g 4

In this table, the labels are along the top row. The first column shows the amount per serving. There is no

unit of measurement listed beside the label because the rows in the column don't share a common unit.

For example, fat is measured in grams, while sodium is measured in milligrams. The second column is

labeled "% Value," and all the numbers in this column are shown as percentages.

The key to interpreting tables is to read the labels carefully. When you understand how a table is

organized, you will be ready to understand the information, draw conclusions, make comparisons, or

answer questions about the table.

Venn diagrams

A Venn diagram is made of two overlapping circles. It is used to show that two or more sets of data have something in common. Here's an example of a Venn diagram that represents the hobbies of two friends, Myra and Shyam:

Myra and Shyam‘s Hobbies

ShyamBowlingPlayingGuitar

MyraKickboxingPlayingChess

(Shared )Hiking

Each circle includes its own set of data. Shyam's hobbies are bowling, playing guitar and hiking. Myra's

hobbies are playing chess, kickboxing and hiking. The activities they have in common can be shown

in the middle where the circles overlap, meaning that these activities apply to both. If something is

not in the overlapping part, it is not shared. You can see that Shyam does not kick-box or play chess.

Reading and Interpreting Pie Charts

A pie chart is used to show how a part of something relates to the whole. This type of graph

makes it possible to view the data quickly and to determine how things are related. A pie chart

consists of a circle that is cut into pieces much like a pie would be cut. Each of the pieces represents

a different set of data.

The pieces are cut based on percentages. The given data must be converted to percentages

before the pie can be cut into its appropriate pieces. The different pieces are usually identified by

a

different colour. A legend is often used to display what the colours represent. The pieces should

also be labeled with the appropriate percentages to help make observations more quickly.

PRACTICE

Let‘s try to answer the questions based on the pie chart. Study the pie chart below and answer the questions that follow:

5

35Jogging

Surfing internet

45 Reading

Outdoor Games

15

I. You interviewed 100 students. Which activity is preferred after surfing internet?

A. Reading

B. Outdoor games

C. Jogging

D. Doing nothing

Answer is B= Outdoor Games. (Surfing Internet is 45% , next highest after that is OutdoorGames standing at 35%)

II. Which is the least popular hobby among the students?

A. Jogging

B. Reading

C. Outdoor games

D. Surfing internet

The answer is A= Jogging (The smallest division or percentage- 5% )

Pie charts are used to represent proportions of a whole. If this type of chart is used to illustrate a

sample of data, look carefully at the sample size. For example the following pie chart shows the

results of a survey for and against tiger hunting:

For

Against

If the sample size is 1000 people, then ¾ of the people are – i.e. 750 people are against tiger hunting. However, if the sample size is only 4, then only 3 people asked are against it.

When interpreting pie charts you may need to work with fractions and/or percentages.

Data is presented in a diagram or a chart to make an immediate visual impact. As such the user

intends you to get the main message instantly. However, you will need to look carefully at it and make sure

that the data has not been presented in a misleading way. You should always:

look at the context of the data

question the validity of the argument illustrated

look at the date.

Reading and Interpreting Bar Graphs

Bar Charts, like pie charts, are useful for comparing classes or groups of data. In bar charts, a class or group can have a single category of data, or they can be broken down further into multiple categories for greater depth of analysis.

When looking at the information contained within a chart or diagram, it is useful to consider:

its title the source of the data the size of the samples used (if appropriate) the date it was produced.

If you are interpreting a bar chart or histogram consider:

the labels on the axes the scale, or scales, used.

If you are interpreting a pie chart or pictogram consider: the key that tells you what parts of the diagram represent.

A bar graph is a visual display used to compare the amounts or frequency of occurrence of

different characteristics of data. This type of display allows us to:

compare groups of data, andto make generalizations about the data quickly.

Ssal

es in

‘000

When reading a bar graph there are several things we must pay attention to: the graph title, two axes, including axes labels and scale, and the bars. Since bar graphs are used to graph frequencies oramounts of data in discrete groups, we will need to determine which axis is the grouped data axis, as wellas what the specific groups are and which is the frequency axis.

An example of a bar graph is given below. The bar chart shows the sales of reference books within a year.

Scale: Tells how many or how much. It contains evenly distributed numbers that represent some unit of measure

The title tells what kind of information is found on the graph

Sales in RM’000 for School Reference Books

900080007000600050004000300020001000

0

Mathematics Bahasa Melayu English Language History

Types of Reference Books sold

Bar Labels- Labels describe individual parts of thegraph

Y axis X axis

Grouped Data Axis

Now let's look at the components of a bar graph individually. There is a lot of information in this section so you may wish to jot down some short notes to yourself.

Graph Title--The graph title gives an overview of the information being presented in the graph. The title is given at the top of the graph

Axes and their labels--Each graph has two axes. The axes labels tell us what information is presented on each axis. One axis represents data groups, the other represents the amounts or frequency of data groups

Grouped Data Axis--The grouped data axis is always at the base of the bars. This axis displays the type of data being graphed.

PRACTICE

Let‘s try to interpret the data from the graph.

I. What is the income from the sales of History books?

A. RM 8000.00

B. RM 8500.00

C. RM 6000.00

The answer is C= RM 6000.00. (refer to the Bar Label for History and the Scale accordingly)

II. What is the difference between the sales of Mathematics books with English Language books?

A. RM 8000.00

B. RM 5000.00

C. RM 3000.00

The answer is C- RM 8000.00(sales of Mathematic Books) minus RM 5000.00 (sales of English

Language books) is equal to RM 3000.00

III. What is the income earned out of the sales of all the reference books as listed in the graph?

A. RM 27500.00

B. RM 85000.00

C. RM 9000.00

The answer is A=RM 27500.00 ( sale of all the books added- RM 8000+RM 8500+RM 5000 + RM

6000)

LINE GRAPHS

Line graphs compare two variables. Each variable is plotted along an axis. A line graph has a vertical

axis and a horizontal axis. So, for example, if you wanted to graph the height of a ball after you have

thrown it, you could put time along the horizontal, or x-axis, and height along the vertical, or y-axis.

Each type of graph has characteristics that make it useful in certain situations. Some of the strengths of

line graphs are that:

They are good at showing specific values of data, meaning that given one variable the other

can easily be determined.

They show trends in data clearly, meaning that they visibly show how one variable is affected

by the other as it increases or decreases.

They enable the viewer to make predictions about the results of data not yet recorded.

PRACTICE: Try to answer the questions below based on the line graph.

Sales in RM ‗000

6543210

January February March April

Magazines

Story Books

Comics

1. How many sets of data are represented?

Answer: The are three(3) sets of data- magazines, story books and comics

2. On which calendar month does the graph begin?

Answer: (January)

3. In what month does the graph reach its highest point?

Answer: (April) The highest sale is RM5,000

Pictograph

Pictograph is a way of representing statistical data using symbolic figures to match the frequencies

of different kinds of data.

Example of Pictograph

The pictograph shows the number of varieties of apples stored at a supermarket.

VARIETIES OF APPLES AVAILABLE

Red Hot

Red Med

Green Dark

Red Small

Red Gold

= 10 apples = 5 apples

Solved Example on Pictograph

Use the pictograph to find the total number of apples stored in the supermarket.

A. 150B. 200C. 250

Solution:

Step 1: The pictograph shows 14 full apples and 2 half apples.

Step 2: So, there are 140 + 10 = 150 apples stores in the supermarket.

TASK 1: Study the pie chart below and answer the questions that follow:

40%

18%

30%

12%

Motorist Pedestrians Lorry Drivers

Motorcyclists

1. According to the graph, the highest accident rate involves…

A. motorists.

B. pedestrians.

C. lorry drivers.

D. Motorcyclists

2. Which of the statements below is true?

A. more than half of the accidents involve lorry drivers and motorists.

B. more than half of the accidents involve lorry drivers and pedestrians

C. more than half of the accidents involve lorry drivers and motorcyclists

A. 10 000B. 20 000C. 22 000D. 30 000

TASK 2: Answer the questions based on the table below:

SMK SERI KANDI

Year 2005 2006 2007 2008 2009

Number ofstudents enrolled

10 000 15 000 18 000 22 000 30 000

Number of Students in SMK Seri Kandi

1. Based on the table above, what is the total number of students studying at the school in 2006 and2007?

A. 15 000B. 18 000C. 30 000D. 33 000

2. What is the difference in the number of students from the year 2005 to 2009

TASK 3: Study the table below and answer the question that follows.

Percentage

% of population using improved drinking-water sources, 2006 urban

100

% of population using improved drinking-water sources, 2006 rural

96

% of population using improved sanitation facilities 2006 total

94

% of population using improved sanitation facilities 2006 urban

95

Which of the following statements is NOT true?

A. Everyone in the urban area enjoy clean waterB. People in the rural area do not enjoy clean water. C. Sanitation facilities still need some improvementD. Sanitation facilities in the urban area is totally improved

TASK 4: Study the table below and answer the questions that follow.

Type of Reading Material Teenagers AdultsNovels 70% 30%

Reference Books 40% 40%

Foreign Magazines 40% 55%

Local Magazines 65% 25%

Malay Newspapers 25% 75%

English Newspapers 20% 65%

Survey of readers' preference in reading material in Perlis

1. Which type of reading material is least popular among teenagers?

A. Local magazines

B. Novels

C. English newspapers

D. Reference books

2. One of the conclusions that can be made from the survey is…A. Most teenagers prefer reading novels to newspapers

B. Most adults enjoy reading local magazines

C. Only a small percentage of teenagers read local magazines

D. Newspapers are popular among teenagers

TASK 5: Study the pie chart and answer the questions that follow.

Typical day of a teenager

Talking on the phone17

33Going to school

Studying

25 Eating

Watching TV8 4 Sleeping

1. What percent of the day is spent watching TV?

2. How many hours are spent sleeping?

3. What activity takes up the least amount of time?

4. What activity takes up a quarter of a day?

5. What two activities take up 50% of the day?

Reading Skills|79

TASK 6: Try answering the following questions by looking at the graph

Hourly Minimum Wage at PRESCO

605040302010

01980 1990 2000 2010

1. What was the minimum wage in 1980?

2. When did the minimum wage reach RM45.00?

3. Between what time periods was the largest increase in minimum wage?

4. Based on your observations of the graph, make a prediction about

what the wage might be in the year 2020.

Reading Skills|80

TASK 7: Based on the illustration, answer the questions that follow.

All flowers share several basic parts. Each begins growing at the end of a branch called a peduncle, which enlarges to become a receptacle. Sepalsprotect the flower‘s ovary,petals surround the stamenand pistil.

1. What is the stem of the flower called?

A. a peduncle B. a receptacle C. an ovary

2. Which types of flowers have the parts shown in the diagram?

A. roses and liliesB. only liliesC. all flowers

Reading Skills|81

TASK 8: Study the price comparison table and answer the questions that follow.

GROCERY STORE PRICE COMPARISONPRODUCT DE STORE PESCO CARE FOR UDISH WASHING LIQUID

RM 2.50 RM 3.60 RM2.90

POTATO CHIPS RM 2.30 RM 2.90 RM3.20HAND SOAP RM 4.70 RM 4.50 RM5.30COOKING OIL RM 4.80 RM 5.40 RM4.30

1. What is the purpose of this table?

2. How many grocery stores are being compared?

3. Which store offers potato chips at the lowest price?

4. Which store charges the most for cooking oil?

5. How much does hand soap cost at Care For U?

6. What is the cheapest product listed in the table?

Reading Skills|82

SUMMARY

Writers have many options for presenting information. Maps, illustrations, tables, time lines, and Venn

diagrams are all visual ways to show information. If they are included in a book or article, they might

be used as evidence and support for the author's argument. If you encounter a map or diagram by itself,

you can use your active reading skills to interpret its meaning. The title, caption, labels, and

unit of measurement are key clues to help you understand how the data is organized.

Reading Skills|83

SELF ASSESSMENT

TEST 1

Study the pie chart and answer the questions that follow.

Monthly Household Expenditure

12.537.5

FOOD

HOUSE

FUEL

1. How much is spent on food and fuel?A. 15%B. 45%C. 50%D. 75%

2. How much is spent on payment for the house?A. Quarter of the total expenditureB. Half of the total expenditureC. Three quarters of the total expenditureD. All of the monthly expenditure