Wednesday 12 June 2019

Process in Mathematics


PROCESSES IN MATHEMATICS:
  • Mathematical reasoning.
  • Pattern recognition.
  • Algebraic thinking.
  • Geometric thinking (Van Hiele model of geometric thought).
  • Problem solving in mathematics.
  • Creative thinking in mathematics.

Mathematical Reasoning
     The best way for child to learn and enjoy mathematics is to be curious, ask a lot of questions and make sense of mathematics through reasoning. It is a teacher’s responsibility to encourage this curiosity in the mathematics class as well. The best way for children to make sense of mathematics is through reasoning. Children learn to use mathematics in meaningful ways by asking a lot of questions and thinking. This enables them to connect different ideas, gain a deeper conceptual understanding and therefore enjoy mathematics. For this, they classroom environment must be such that children are encouraged to ask a lot of questions, the teacher must be prepared to answer/facilitate these questions patiently without judging the children; essentially the classroom environment must be free from fear.   

What is reasoning?

See the example in Table-1 below. Both Student-1 and Student-2 have reasoned their answers. Notice that the teacher was not satisfied with the correct answer, but asked the students to explain how they solved it. By explain the solution, students are able to make sense of the mathematics. The teacher clearly knows from the students’ response that they not only know how to add, but they have also conceptually understood what the”=” sign represents in the problem. Reasoning enables deeper conceptual understanding. 


Table-1


Teacher (to the class): Can you solve this problem?
                                     16+27=   (  ) + 30
Student-1: 13
Student-2: 13
Teacher: How did you solve it?
Student-1: Thirty is three more than twenty seven, so if I subtract 3 from 16, I will get 13.So 13 is the correct to make the two sides equal”.
Student-2: “Sixteen plus twenty seven is equal to forty three. Forty three minus thirty is equal to thirteen. So 13 is the correct answer.



In mathematics theory we say that there are three main components to the reasoning process. They are justifying,conjecturing and generalizing. These terms may sound complicated, but they are very simple to understand.    
1.      Justifying: Justifying is to make a logical argument or reason based on an idea that has already been understood. The explanation that Student-1 and Student-2 gave in table -1 above are examples of justification. These students have already understood addition, the meaning of the equal to sign (=) in the equation the teacher wrote and justified their answers to the given problem.
2.      Conjecturing: A conjecture involves reasoning about mathematical relationships and making a statement that is thought to be true, but is not known (by the person making the statement) to be true. It is usually made on the basis of incomplete information. In the example below (Table-2), the student sees a pattern; (every time two even numbers are added the sum is always an even number) and makes this conjecture. The student did not know this previously and makes this statement based on just the sums she/he sees on the black board (incomplete information). It is thought to be true by the student but he/she has not proved it to be true by any formal methods.
Table-2

Teacher presents each of the following problems. He guides students to identify a pattern (that when two even numbers are added the sum is also an even number).                                       
                      2 + 4  =   6
                      12+14 =26
                       4 + 8  =12
One Student makes the following conjecture:
 “When we add two even numbers, the sum is also an even number”

3.     
4. Generalizing: 
A conjecture that is considered to be true is a generalization. Generalization is also involve reasoning about mathematical relationships, seeing patterns and extending the reasoning beyond the scope of the original problem, where a new insight is formed.
For example, in table-3 student and teacher make a generalization.

Table-3


The teacher is provoking students to see a pattern and make conjectures.
                                 2 + 0 = 2
                                 3+ 0 = 3
                                 4+ 0 = 4 and so on
One student makes a conjecture by saying
“When we add zero to any number, the sum is always the same number”.
The teacher explains that this is true for all positive integers and writes it more formally as,
 X + 0 = X; where x is any positive integer.










          It is important to remember that when every child has an opportunity to reason and make sense of the mathematics that is being taught in school, that they develop deeper conceptual understanding of topics in mathematics. When children develop conceptual understanding of their mathematics then they begin to enjoy learning and doing mathematics. It is interesting to observe that there are different types of reasoning done in mathematics. It is interesting to observe that there are different types of reasoning done in mathematics.
      Mathematics is also called the science of reasoning. According to Locke, “Mathematics is a way to settle in mind a habit of reasoning. “ Reasoning in mathematics is of two types: 1) Inductive reasoning and 2) Deductive reason.




Inductive reasoning
   When statements containing mathematical truths are based on general observations and experience, reasoning is called inductive reasoning.
       Inductive reasoning is bottom-up, that is broad generalizations (or general rules) are made from a specific observations and cases.  Inductive reasoning is a logical process in which multiple premises, all believed to be true or found true most of the time, are combined to obtain a specific conclusion. In Inductive reasoning, we notice a trend or a pattern and make an informed guess (conjecture) based on that pattern. The resulting generalization may not necessarily be true.
          All the above examples shown in Table 1, 2 and 3 are examples of inductive reasoning.
Inductive reasoning (as opposed to deductive reasoning or adductive) is reasoning in which the premises are viewed as supplying strong evidence for the truth of the conclusion. While the conclusion of a deductive argument is certain, the truth of the conclusion of an inductive argument is probable, based upon the evidence given.[1]
           Many dictionaries define inductive reasoning as reasoning that derives general principles from specific observations, though some sources disagree with this usage.[2]
         The philosophical definition of inductive reasoning is more nuanced than simple progression from particular/individual instances to broader generalizations. Rather, the premises of an inductive logical argument indicate some degree of support (inductive probability) for the conclusion but do not entail it; that is, they suggest truth but do not ensure it. In this manner, there is the possibility of moving from general statements to individual instances (for example, statistical syllogisms, discussed below)
DEDUCTIVE REASONING
Deductive reasoning is a type of reasoning that is top-down. It is a process by which we begin with one set of facts and deduce some other sets of facts. Deductive reasoning is the process of resoning from one or more statements to reach a logically certain conclusion. It is a logical reasoning process which proceeds from a general rule to a specific instance, unknown to known or abstract to concrete.
     The example in table-5 below is a process of deductive reasoning.  In this example we started with some facts (definition of even integers) and logically deduced that the sum of two even integers is even. This conclusion is logically certain.
Table-5
Example-1:
Hypothesis: The sum of any two even integers is even.
Proof: Let a and b be even integers.
We have that a=2n and b=2m. (by definition of even numbers)
Consider the sum a + b= 2m + 2n= 2 (n +m)=2k where k= n + m is an integer.
Therefore the sum of a + b= 2k (by definition of even numbers we have shown that the hypothesis is true)







 Example-2                                                            D            B           E
 


                                                                                A                      C
Theorem: “Sum of the three angles of a triangle is equal to two right angles”
Data: ABC is a triangle.
To Prove:BAC + ABC +ACB
Construction: Draw a line DE parallel to side AC and passing through vertex B.

Statement                                                            ___________________________ 
_Triangle ABC with  angles A,B,C
DBA = BAC



Reason
_______________________________
Given:
Lines DE and AC are parallel and Angles formed by two parallel lines and a transversal (Alternative angles are equal)
EBC = BCA



Lines DE and AC are parallel and Angles from 2 parallel lines and a transversal(Alternative angles are equals)
DBA+∟ABC + ∟EBC = 1800

Supplementary angles

Therefore, BAC+ABC+ACB =1800


By Substitution

Therefore Sum of the three angles of a triangle is equal to two right angles.
A right angle = 900


























       Deductive reasoning, also deductive logiclogical deduction is the process of reasoning from one or more statements (premises) to reach a logically certain conclusion.[1] It differs from inductive reasoning and deductivereasoning.
    Deductive reasoning links premises with conclusions. If all premises are true, the terms are clear, and the rules of deductive logic are followed, then the conclusion reached is necessarily.
        Deductive reasoning (top-down logic) contrasts with inductive reasoning (bottom-up logic) in the following way: In deductive reasoning, a conclusion is reached reductively by applying general rules that hold over the entirety of a closed domain of discourse, narrowing the range under consideration until only the conclusion(s) is left. In inductive reasoning, the conclusion is reached by generalizing or extrapolating from specific cases to general rules, i.e., there is epistemic uncertainty. However, the inductive reasoning mentioned here is not the same as induction used in mathematical proofs – mathematical induction is actually a form of deductive reasoning.
          Deductive reasoning, this type of reasoning is based on certain postulates or axioms and in this statements are products of mind. We try to compare and contrast various statements and then draw out conclusions from such a comparison. Essentials of a deductive reasoning are as follows:
      * Undefined terms-----point, surface etc.
      * Definitions
      * Postulates and Axioms.
Reasoning:
  • Justify why an answer or approach to a problem is reasonable;
  • Make and test generalization or observation;
  • Make prediction or draw conclusions from available information;
  • Analyze statements and provide examples which support or refute them;
  • Judge the validity of arguments by applying inductive and deductive thinking;
Problem Solving:
  • Use information to identify and define the question/s within a problem;
  • Make a plan and decide with information and steps are needed to solve the problem;
  • Choose the appropriate operation/s for a given problem situation;
  • Select and apply appropriate problem-solving strategies  to solve a problem from visual(draw picture, create a graph), numerical (guess and check, look for a pattern), and symbolic(write an equation) perspectives;
  • Organize, interpret, and use relevant interpretation;
  •  Select and use appropriate tools and technology;
  • Show that no solution or multiple solutions may exist;
  • Identify alternate ways to find a solution;
  • Apply what was learned to a new problem.

Creating classrooms that Encourage Reasoning
   There are many ways to create a mathematics classroom environment that encourages mathematical reasoning. Some useful pointers are given below:
1.      The teacher must encourage children to ask plenty of questions and also ask many questions.
2.      A significant amount of time must be spent discussing and talking mathematics in the class. Teacher can make statement like-“when we add an odd number and an even number the sum is an odd number” and ask the children if this statement is (Always, sometimes or never) true. The teacher must also ask the students to justify their answers.
3.      Teachers should not dismiss wrong answers, but encourage the children to justify their answers and in this process sometimes children self-correct their mistakes. Otherwise the teacher can intervene at the appropriate time and help the child find his/her error.
4.      Mathematics classes are not only about drill and solving sums in notebooks. The classroom must include talking mathematics. Only when children talk mathematics they are able to available on the internet, the teacher can choose suitable age and topic
5.      Encourage children to create their own word problems, this also helps children to reason.
6.      Teachers must frame rich questions, in such a way that children learn how to make conjectures, generalizations and justify their answer. (Give an example).
7.      connect the language they speak with the symbols and language of mathematics and make connections with the real world and mathematics.
8.       There are appropriate puzzles for students to solve in groups, alone or as a whole class.many mathematics puzzles


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