## 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.