Introduction
We saw that our food and clothes have so much variety in them. Not just food and clothes, there is such a vast variety of objects everywhere. We see around us, a chair, a bullock cart, a cycle, cooking utensils, books, clothes, toys, water, stones and many other objects. All these objects have different shapes, colours and uses.
All objects around us are made of one or more materials. These materials may be glass, metal, plastics, wood, cotton, paper, mud or soil.

Activity–1
AIM : To find out some common materials around us and their objects
Different types of objects that are made from the same material
    Material             Objects made of these materials                      
    Wood                Chair, table, plough, bullock cart and its wheels, ...
    Paper                Books, notebooks, newspaper, toys, calendars,...
    Leather                
    Plastics
    Cotton

Above table lists some common materials. We can also add more materials in Column 1 that are known. Now, try and think of everyday objects, that are made mainly of these materials, and list them in 
Column 2.
First, we grouped objects in many different ways. We then found that objects around us are made of different materials. At times, an object is made of a single material. An object could also be made of many materials. And then again, one material could be used for making many different objects. 

There are various types of utensils in the shop owned by Rohan's Father.

These are 

  1. Copper Jar
  2. Iron Pan
  3. Plates made of Steel
  4. Glass tumblers
  5. Utensils made of Clay

Rohan's Father keeps similiar utensils in the same shelf that is called sorting of Material.The material can be grouped together based upon their characterstics such as shape,size , color ,material made to make it etc. This not only helps to differentiate the material but also makes it easy to pick the utensil of one's choice from the whole lot.