How_To_Be_Good_At_Math

286 STATISTICS •^ DRAWING BAR CHARTS

Drawing bar charts

To draw a bar chart you need a pencil, a ruler, an eraser,

coloured pens, pencils, or crayons, and squared paper

or graph paper. Most importantly, you need some data!

First, we draw a horizontal

line for the x axis and

a vertical line for the y axis.

Next we draw marks on

the x axis to show the width

of the bars that represent the

different instruments. All the bars

must be of the same width. Let’s

make ours 2 small squares wide.

Let’s use the data in this

frequency table. It shows the

results of a survey of instruments

played by a group of children.

Now let’s add a scale to the

y axis to represent the

number of children. We need a

scale that covers the range of

numbers on the table but doesn’t

make our chart look stretched or

squashed. A scale from 0 to 8

works well here.

It’s best to draw our bar

chart on paper marked

with small squares. This

makes it easier to mark a

scale and draw the bars.

Guitar 7

Violin 6

Trumpet 3

Flute 4

Piano 5

Numbers in

this column

show the

frequency

What instrument do you play?

Instrument Children

Vertical axis

Each bar is

2 small

squares wide

Draw marks to

show where

each bar will

begin and end

Horizontal axis

Squared

paper

NUMBER OF CHILDREN

0

1

2

3

4

5

6

7

8

Guitar

INSTRUMENT

Violin Trumpet Flute Piano

Draw your bar charts

on squared paper.

286_287_Drawing_bar_charts.indd 286 29/02/2016 18:06