Maharashtra Board Class 6 Maths part 1 Chapter 6 Bar Graphs PDF Download

Bar Graphs

Let's Recall

Observe the picture alongside.

To which sport is this data related?

How many things does the picture tell us about?

What shape has been used in the picture to represent runs?

We have seen how to make pictograms for given numerical data. When the scale is given, numerical information can be obtained by counting the pictures.

Example: A pictogram of the types and numbers of vehicles in a town is given below. Taking 1 picture = 5 vehicles, write their number in the pictogram.

It can take a long time to draw pictures. Could we give the same data without using pictures?

Teacher's Note

Bar graphs help us see data quickly. Just like we see the cricket score bars on TV, we can show any information with bars.

Exam Trick

Remember: Pictogram = pictures, Bar graph = bars. Bar graphs are faster to draw than pictures!

Points to Remember

Pictograms use pictures to show data.
We count the pictures to find numbers.
Bar graphs use bars instead of pictures.
A scale tells us what each picture means.

Graph Paper

Let's Learn

Observe the graph paper shown here.

There are some bold and some faint lines on it. The bold lines show a certain big unit. This unit is divided into smaller units which are shown by the faint lines. The grid formed by these lines makes it easy to select a suitable scale and draw columns of the proper height.

Near the lower edge of the paper, a horizontal line is drawn as a base. It is called the X-axis. A line perpendicular to the X-axis is drawn on the left side of the paper. That is called the Y-axis.

The items about which the graph is to be drawn are taken on the X-axis at equal distances from each other. The number related to each item is shown above it by a vertical column. This column is parallel to the Y-axis and of the proper height according to the chosen scale.

Now, let us convert the pictogram shown on page 35 into a bar graph.

In the graph, we have to show certain vehicles and their number, which are 5, 15, 25 and 30. Let us take a scale of 5 vehicles = 1 big unit.

You can see the finished graph in the figure above.

Teacher's Note

Graph paper has lines that help us draw straight bars. In India, we use graph paper in all schools for math and science.

Exam Trick

Remember: X-axis goes left to right, Y-axis goes up and down. X is horizontal, Y is vertical - like making an "X" mark!

Points to Remember

X-axis is the horizontal line at the bottom.
Y-axis is the vertical line on the left.
Both axes meet at point O.
Scale tells us how much each unit means.
Items go on the X-axis, numbers go on the Y-axis.

Drawing a Bar Graph

Let's Learn

This bar graph shows the maximum temperatures in degrees Celsius in different cities on a certain day in February. Observe the graph and answer the questions.

What data is shown on the vertical and the horizontal lines?

Which city had the highest temperature?

Which cities had equal maximum temperatures?

Which cities had a maximum temperature of 30°C?

What is the difference between the maximum temperatures of Panchgani and Chandrapur?

Let us take an example to see how the given data is shown as a bar graph.

Example: Information about the plants in a nursery is given here. Show it in a bar graph.

Take a graph paper.

In the centre, write the title "Types and number of plants".

Draw the X and Y axes, and mark O, their point of intersection.

Write the names of the plants on the X-axis at equal distances.

The number of plants is divisible by 5. So, take the scale 0.5 cm = 5 plants, that is, 1 cm = 10 plants on the Y-axis as it can be easily shown on the graph paper.

Write the scale in the top right hand corner.

Draw a bar of the appropriate height above the name of each plant on the X-axis.

Teacher's Note

Bar graphs show information with tall and short bars. If you see water used by families in a village, you make bars - taller bar means more water used.

Exam Trick

Remember: All bars must have equal width. The space between bars must be equal. This makes your bar graph look neat and correct.

Points to Remember

Write a title at the top of your graph.
All bars must be the same width.
Spaces between bars must be equal.
Each bar's height shows the correct number.
Always write the scale on your graph.

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