Page 333 - Start Up Mathematics_8 (Non CCE)

MATHS LAB ACTIVITY

Objective: To collect data and represent it in the form of a histogram
Material required: White sheet of paper, scale, pencil, graph sheet
Step 1: Prepare a table in the given format. Fill it by asking your classmates about the number of hours
they watch TV in a week.
Name of the Watching TV
S. No.
student (in hours)
1
2
3
Step 2: Group the data into class intervals and fill it in a table of the given format:

Watching TV (in hours) Tally marks Number of students
(Class intervals) (Frequency)

Step 3: Now represent the above data in the form of a histogram. Y

Number of students

Observations:
1. Maximum number of students watch TV for ________ hours per week. Watching TV X
2. Number of students who watch TV for less than 3 hours a week is ________. (in hours)
3. Number of students who do not watch TV is ____________.

You can also do this activity by noting down the number of hours each member of your family spends
on watching TV in a week. Prepare a histogram and find out who watches TV for maximum number
of hours.

Pie Chart (or Pie Diagram)

A pie chart is a pictorial representation of numerical data in a circle divided into sectors. Each sector is
proportional to the component part or information it represents. A pie chart is also called circle graph.

Drawing a pie chart
Step 1: Obtain the data and find the sum of various component values.
Step 2: Calculate the central angle for each component by using the formula:

Ê Valueofthe component ˆ
Central angle of a component = Á 360¥ ˜
Step 3: Draw a circle of any radius. Ë Totalvalue of allthe components ¯ ¯
Step 4: Draw a horizontal line as the radius of the circle.
Step 5: Starting with this horizontal radius and moving in clockwise direction, draw sectors using the
central angles calculated in step 2 one at a time till all the components are exhausted.
Step 6: Shade the sectors using different colours/designs and name them.

325