Friday, May 20, 2011

Module 8: Laboratory Method

LABORATORY METHOD INTRODUCTION


Ø  This method is based on the maxim “learning by doing.”
Ø  This is an activity method and it leads the students to discover mathematics facts.
Ø  In it we proceed from concrete to abstract.
Ø  Laboratory method is a procedure for stimulating the activities of the students and to encourage them to make discoveries.
Ø  This method needs a laboratory in which equipments and other useful teaching aids related to mathematics are available.
Ø  For example, equipments related to geometry, mensuration, mathematical model, chart, balance, various figures and shapes made up of wood or hardboards, graph paper etc.







Procedure:
Ø  Aim of The Practical Work: The teacher clearly states the aim of the practical work or experiment to be carried out by the students.
Ø  Provided materials and instruments: The students are provided with the necessary materials and instruments.
Ø  Provide clear instructions: Provide clear instructions as to the procedure of the experiment.
Ø  Carry out the experiment: The students carry out the experiment.
Ø  draw the conclusions : The students are required to draw the conclusions as per the aim of the experiment.

Example  1:
Derivation of the formula for the volume of a cone.
Aims: to derive the formula for the volume of a cone.
Materials and instruments: cone and cylinders of the same diameter and height, at lease 3 sets of varying dimensions, sawdust, water and sand.
Procedure: ask the students to do the following activity.
v  Take each pair of cylinder and cone having the same diameter and height
v  Note down the diameter and height
v  Fill the cone with saw dust / water or sand and empty into the cylinder till the cylinder is full.
v  Count the number of times the cone is emptied into the cylinder and note it down in a tabular column.
v  Repeat the same experiment with the other two sets of cone and cylinder and note down the reading as before.
S.NO.
DIAMETER OF CONE / CYLINDER
HEIGHT OF CONE/ CYLINDER
NO. OF MEASURES OF CONE TO FILL THE CYLINDER
1
3 CM
5 CM
3
2
5 CM
7 CM
3
3
6 CM
10 CM
3


Drawing conclusions:
Each time, irrespective of the variations in diameter and height it takes 3 measures of cone to fill the cylinder.
Volume of cone = 1/3 volume of cylinder
But volume of cylinder = Õ r2 h
Volume of cone =1/3 Õ r2 h

Example 2:
Sum of three angles of a triangle is 180 degree. “How we can prove this in the laboratory.
Aims:
To prove that sum of the three angles of a triangle is equal to two right angles or 180 degree.
Materials and instruments:
Card board sheet, pencil, scale, triangle and other necessary equipments.
Procedure:
In the laboratory pupils will be given on cardboard sheet each and then they are told how to draw triangles of different sizes on it. After drawing the triangles they cut this separately with the help of scissors.
Observation:
Student will measure the angles of the triangles drawn and write these in a tabular form
Figure no.
Measure of different angles
Total
Angle A +B+C
Angle A
Angle B
Angle C
1
90
60
30
180
2
120
30
30
180
3
60
60
60
180

Calculation: after measuring the angles of different triangles in the form of cardboard sheet. We calculate and conclude their sum.
In this way by calculating the three angles of a triangle the students will be able to conclude with inductive reasoning that the sum of three angles of a triangle is 180 degree or two right angles.

Some More Topics for Laboratory Method
Derivation of the formula for the 
Ø  Circumference of a circle, area of circle
Ø  Area of square, rectangle,, parallelogram, and trapezium
Ø  Area of triangle, right angled triangle, isosceles right angles triangle
Ø  Total surface area of cone, cylinder
Ø  Volume of a sphere
Ø  Volume of a cone
Expansion of identities such as (a+b) 2, (a-b) 2 , (a+b+c) 2
Verification of
Ø  Properties of certain geometrical figures like parallelogram, rhombus etc
Ø  Angle sum property in a triangle
Ø  Congruency postulates
Ø  Theorems relating to triangles, circles and transversal properties.

Merits:
Ø  The method is based on the principle of learning by doing.
Ø  This method is psychological as we proceed from known to unknown.
Ø  It is based on the student’s self pacing.
Ø  It helps in making clear certain fundamental concepts, ideas etc.
Ø  It develops the self-confidence and teaches the students the dignity of labour.
Ø  The children learn the use of different equipments, which are used in laboratory.
Ø  It develops in the child a habit of scientific, enquiry and investigation.
Ø  This method presents mathematics as a practical subject.
Ø  It stimulates the interest of the students to work with concrete material.
Ø  It provides opportunities for social interaction and co-operation among the students.
Ø  It is child-centred and therefore it is a psychological method.
Ø  It helps the students to actively participate in the learning process and therefore the learning becomes more meaningful and interesting.

Demerits:
Ø  This method can be used for a small class only.
Ø  It requires a lot of planning and organization.
Ø  This method is suitable only for certain topics.
Ø  This method it is not possible to make progress quickly.
Ø  This method requires laboratory equipped with different apparatus.
Ø  All mathematics teachers cannot use this method effectively.
Ø  It is an expensive method. All schools are not able to adopt this method.
Ø  This method has very little of theoretical part in it.


Conclusion
          In conclusion we can say that this method is suitable for teaching mathematics to lower classes as at this stage teaching is done with the help of concrete things and examples.

Module 7: Heuristic Method

HEURISTIC METHOD INTRODUCTION

           The word ‘Heuristic’ has been derived from the Greek word ‘Heurisco’ which means ‘I find’ or ‘I discover’ . This method implies that the attitude of students shall be that of the discoveries and not of passive recipients of knowledge. Armstrong originally introduced this method for learning of science. This method emphasis experimentation as the teacher becomes on looker and the child tries to move a head independently without any help. This method makes the student self-reliant and independent. But the teacher should develop the heuristic attitude by making a lot of preparation. The question should be so planned that it may be possible for the students to find the solution independently by proceeding in the proper direction.




DEFINITION
          According to H.E.Armstrong, “This is the method of teaching which places the pupils as far as possible in the attitude of a discoverer.”
          According to westaway, “the heuristic method is intended to provide training in method. Knowledge is a secondary consideration altogether.

Example 1:
          The population of a city is 50,000. The rate of growth in population is 4% p.a. what will be the population after 2 years?

Teacher         :        what we have to find out in the given question
Student         :        population after two years.
Teacher         :        how can we find it?
Student         :        first we find the population after 1 year.
Teacher         :        what is the growth of every year?
Student         :        rate of growth is 4% p.a.
Teacher         :        what will be the population in the end of first year?

Student         :        population after 1 year = 50000 + 50000x 4/100
                                                          = 50000 + 2000 = 52000
Teacher         :        what will be the base population for second year?
Student         :        the base population of second year is 52000.
Teacher         :        how can we find the growth?
Student         :        the growth of second year = 52000 x 4 /100 = 2080
Teacher         :        what will population after two years?
Student         :        population after two years = 52000 + 2080 = 54080

Example 2:
Prove that a0 = 1
Teacher         :        what is 10/5?
Student         :        2
Teacher         :        what is 5/5?
Student         :        1
Teacher         :        what is 7/7?
Student         :        1
Teacher         :        what is a/a ?
Student         :        1                          
Teacher         :        what is am/am ?
Student         :        1.                                 Equation I
Teacher         :        how do you get the result?
Student         :        if we divide a number by itself , we will get 1.
Teacher         :        how can you write am X 1/am  ?

Student         :        am-m = a0                   Equation II
Teacher         :        what do you infer?
Student         :        a0    = 1





Merits
Ø  This is a psychological method as the student learns by self-practice.
Ø  It creates clear understanding
Ø  It is a meaningful learning
Ø  The student learns by doing so there is a little scope of forgetting
Ø  It develops self-confidence, self-discipline in the students
Ø  The students acquire command of the subject. He has clear understand and notions of the subject.
Ø  It gives the student a sense of confidence and achievement.
Ø  The methods make them exact and bring them closer to truth.
Ø  It inculcates in the student the interest for the subject and also develops willingness in them.


Demerits:
Ø  It is not suitable for lower classes as they are not independent thinkers. Discovery of a thing needs hard work, patience, concentration, reasoning and thinking powers and creative abilities.
Ø  It is very slow method. That is time consuming method.
Ø  It is lengthy.
Ø  The students have to spend a lot of time to find out minor results.
Ø  The teacher may find it difficult to finish the syllabus in time.
Ø  It does not suit larger classes.
Ø  It suits only hard working and original thinking teachers.
Ø  A method is successful if well-equipped libraries, laboratories and good textbook written in heuristic lines but such facilities are lacking in our school.

Conclusion
          Heuristic method is not quite suitable for primary classes. However, this method can be given a trail in high and higher secondary classes.