4th Class Mathematics Data Handling Data Handling

LEARNING OBJECTIVES

This lesson will help you to:—

• collect data from different sources.
• record data using tally masks.
• prepare tables for recording data.
• represent data in terms of pictograph choosing appropriate unit for displaying data.
• represent data in terms of bar graphs choosing appropriate unit for displaying data.
• represent data in terms of pie-chart.
• recognize patterns in the data.
• draw inferences from the data.

Real Life Example

• Data handling is widely used in collection of scores of students in various exams and marking ranks to the students.
• Pictographs are used by newspapers and magazines to attain the attention of the readers.
• Classrooms are often full of pictographs, for example, charts for lunch, attendance, reading groups or learning centers.
• Pictographs are also used by carious news and channels to display weather report on TV.
• Bar graph helps us to compare population of several different countries at one time.
• We could use a bar graph to display the number of different types of cars in the city. The horizontal axis could have the car names on it like Toyota, Honda, Suzuki, etc. and the vertical bars will become the scale in this example showing the number of cars. Each vertical bar would have a different length which would represent the number of the type of car.

QUICK CONCEPT REVIEW

Diagrams/pictures

Data handling is a process of collection organization and representation of data in various forms. Data is | collected from different sources: then the collected data is organized in order to record it for further use. The recorded data is then represented using graphs and charts.

Process of Data Handing

Favourite ice-cream of students of class 4.

Step 1: Collection of data

Ask each student about their favourite ice cream and note down in you notebook.

Step 2: Organization of data

For organization of data use tally marks against each ice cream and prepare a table.

Use of tally marks:

Write ‘I’ for 1 student against the ice-cream.

Write ‘II’ for 2 student against the ice-cream.

Write ‘III' for 3 student against the ice-cream.

Write "IIII' for 4 student against the ice-cream.

Write’\[\cancel{|||||}\]’for 5 student against the ice-cream.

Write '\[\cancel{|||||}|\]' for 6 student against the ice-cream.

Write '\[\cancel{|||||}||\]' for 7 student against the ice-cream.

Write '\[\cancel{|||||}|||\]' for 8 student against the ice-cream.

Write '\[\cancel{|||||}||||\]' for 9 student against the ice-cream.

Write '\[\cancel{|||||}\cancel{|||||}\]' for 10 student against the ice-cream.

For example:

Step 3: Recording the data

For recording the data prepare a table for the ice-cream and number of students who likes that ice-cream.

Amazing Facts

Data handling is also known as statistics.

The horizontal and vertical lines in the bar graph is called axes of bar graph.

Historical Preview

• Pictograph was the earliest form of writing. It was also the first alphabet, pictograph lasted from about 3000 B.C. to about the 18^th
• The pictograph was invented by sumerians who lived in Sumer. Sumer is in mesopotamia.
• The pictograph is also very similar to Egyption hieroglyphics.
• Most ancient people wrote pictograph on stone or clay with a stylus made out of long reads, wood or bone with a narrow, rectangular head.
• William Play fair was the founder of graphical methods of statistics.
• William Playfair invented bar charts in 1786.
• Pie-chart is credited to William Playfair when he produced a publication ‘The Statistical Brevary’ in 1801 that combined a series of pie diarams.

Step 4: Representation of data

Data is represented using graphs and charts. Here, we would show you representation of data through:

1. Pictograph
2. Bar graph
3. Pie-chart
4. representation of data using pictograph (Refer Table 2)

B. Representation of data using bar graph (Refer Table 2)  

1. Representation of data using Pie-chart

Consider the following data: There are 20 students in class 4. Out of them 5 like vanilla ice-cream and rest of them does not like vanilla ice-cream.

i.e.,\[\frac{5}{20}\]students of class 4 likes vanilla ice cream.

\[\therefore \]The pie-chart becomes

Students of class 4

Thus, using the above given four steps one can perform the task of data handling for various forms of data available in various sources.

Misconcept/Concept

Misconcept: The number of pictures in a pictograph represents the frequency and one picture means 1 object.

Concept: The number of pictures in a pictograph represents the frequency but one picture does not always represent 1 object.

For example: Number of cycles sold in 3 days.

Shortcut to problem solving

• Read the data carefully as the smallest detail may change the meaning of the whole data collected. For example, if you are collecting data about number of students who likes mango or apple and a student says he/she does not like apple, then that does not mean he/she likes mango.
• Record the data in tabular form because tables help to understand the data.
• Try to understand the data provided carefully before jumping to answer the questions.
• Relate the data given in table with charts and graphs and draw them to have better understanding of it.
• Be very careful of the units used in the tables. For example, height of students in cm or feet.
• Take of the scale used in charts and graphs. For example, 1 picture of cycle = 10 bicycles, etc.

Examples:

1. A Pictograph showing number of students going school through different modes of transport.

2. A bar graph showing number of students and their favourite fruit.