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Subjects /Class 7 / Mathematics.7 / Data Handling

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26 Sep 2021

In our day to day life, we see various kinds of tables which consist of numbers, figures, names, etc.

These tables provide ‘Data’.

Data is a collection of numbers gathered to give some information.

In this chapter, we will look at some common forms of data that you come across.

Recording Data

  • Each and Every data can be collected from different sources.
  • Recording of data depends upon the requirement of the data.
  • Everybody has different ways to record data.
  • It is possible only when we adopt some suitable system of collecting data.

Organization of Data

  • Raw data is difficult to read, so we have to organize it in such a way so that we can use it in need.
  • If we want to get any type of particular information from the given data quickly, data can be organized in a tabular form
  • The data is represented in a tabular form using frequency distribution and the tally marks.

Concepts of Data Handling

Meaning of Range

  • The difference between the highest and lowest observations in a given data is called its range.

Mean or Arithmetic Mean:

  • Average is a number that represents or shows the central tendency of a group of observations or data.
  • Arithmetic mean is one of the representative values of data.
  • The average or Arithmetic Mean (A.M.) or simply mean is defined as follows:

Define Mode:

  • Mode is another form of central tendency or representative value. The mode of a set of observations is the observation that occurs most often.


  • Median is the middle most observation of the data arranged in ascending or descending order.

Bar Graph:

  • A bar graph is a representation of numbers using bars of uniform widths.

Double bar graphs:

  • It help to compare two collections of data at a glance.

Meaning of Probability

  • A coin has two sides, either Head or tail.
  • So, when you toss the coin, either Head or tail may come.
  • But, you can’t predict whether head or tail will come.
  • There is a chance that Head may come when you toss the coin. Similarly, there is chance for tail to come
  • So, the situation which may or may not happen, is said to have a chance of happening.
  • This means that there is a chance for head to come or not come. This is called chance of happening.

 Important Note:

  • The probability of an event which is certain to happen is ‘1’.
  • The probability of an event which is impossible to happen is ‘0’.