Final Cover - For Printing

The child with visual impairment can be assisted to understand this concept, with the

provision of a set of objects and the grouping of the objects in different combinations.

The only area that the child may have little difficulty is in the formation of a null set,

which is impractical, and could very well be explained by the teacher orally.

The idea of null set may be tried out using a class room situation also. Suppose a
school gets over at 4 p.m. A teacher wants to meet three students namely A,B and C
after the final bell rings. Then the different possibilities that the teacher meeting the
three students together, in groups or individually are listed as follows:

a. A,B,C

b. A,B

c. B,C

d. C,A

e. A

f. B

g. C

h. None, which is the null set.

The idea may be followed to teach the concept of power set also.

16. Proper Subset
    For a set, the subsets other than the given set are called as proper subsets.

In the example given in item 15, {1}, {2} and { } are proper subsets for the given set.

17. Improper Subset
    For a set, the given set itself is said to be the improper subset.

In the example given in item 15, the given set {1, 2} is the improper subset.