here i will give you one of my experiences in teaching PMRI. though this design may be not perfect, i hope it will help teachers to have alternative way in teaching factor and prime number.
Background
For some students mathematics becomes
something that very frightening and frustrating. They thought mathematics not
only was very hard to understand but also need to be memorized so that they can
get a better mark.
Prime and factor of a number were
one of materials that student could not grasp the real meaning behind it. Even
months after they were taught this material, they easily forget about the prime
numbers or the factor of a number.
Characteristic
of RME
There are 5 characteristics which
have to be consulted when one design the instructional activities in teaching
and learning. Those characteristic are:
1. The use of
context in phenomenological exploration
As prime
numbers and factors are hardly seen in daily life except for their application
in cryptography, the concept of these materials should be brought to
mathematics land. Of course the concept should be close and quite realistic for
students. In this case, the concept of those two come from multiple, a material
that students already know and I believe they know the meaning of that
material.
2. The use of
models for progressive mathematization
Models are
used as a bridge from concrete level to a more formal level. In this case the
students will be brought to understand the concept of the material by
experienced the multiplying numbers. Then in the end of this process student
will be able to understand the notion of prime numbers and factor of a number.
3. The use of
students own construction and production
In the activity,
the students are given the opportunity to solve some problems by themselves.
They have the chance to solve the problem in their own strategies. In the end
of this activity, there will be a class discussion to choose what the most
efficient way to solve the problems is.
4. The
interactivity in teaching process
The
activities in the teaching process are designed so that students can take a
part in solving a problems or finding the meaning of the materials. Teacher in
the class will be a facilitator that will support and help the students to
understand.
5. The
intertwining of various mathematics strands or units
The
sequence of instructional activities not only emphasizes the meaning of factor
and prime and strategy to solve the problems, but also stress the relation
between factor and prime number and to multiple numbers.
HLT
There will be a sequenced of
activities that designed in a way to reach the aim of the lesson. The
activities will be describe in table below
Activity
|
Goal
|
Description of activity
|
Conjecture
|
Working with
multiple
|
-
Student can relate factor of a number and the multiplication
-
Students understand the prime number is the number which have exactly
two factors
|
-
Teacher provides a teaching aid (related to multiplication of a
number) where the student will use that.
-
Teacher provides a student worksheets to guide the students
understand about the materials
|
-
Some student will easily find the multiplication using their memory
of it
-
Some student will count the boxes in teaching aid so that they can
get the multiplication product
-
Some student will use a paper and a pencil to count the
multiplication
|
Working with
prime number
|
-
Student can find a strategy to determine whether a given number is a
prime number
|
-
teacher will provides a problem where students should solve related
to determine a number whether it is prime or not
-
two groups will present their solutions
|
-
Some students will try to find a multiplication to get the number.
-
Some students will get the answer by divide the questioned number by
numbers that they guess
|
Result and
analysis
In this part of report, there will
be a comparison between HLT and the actual teaching learning process.
Activity 1
In this first activity, the teacher
presented a teaching aid that will help the students to grasp the meaning of
factor and prime numbers.
The teacher let the students to
stick the sticker in the board in terms they should stick it in the
multiplication of the number in the sticker. Students do this activity until
all of the stickers run out.
Every time students stuck a number,
teacher reminded the students what is the multiplication of that number.
In this activity, most of students
did not have any problems with multiplication of numbers under 11. Most of them
can easily find which number is a multiplication of a particular number.
However, some of students are still have a difficulty in multiplication fact.
This quite became obstruction in the teaching learning process.
For numbers more than 12 most of
students counted the number of the boxes in the teaching aid. However, some
student tended to be incorrect when they counted the boxes, so there were some
stickers which were misplaced.
After finishing the teaching aid,
teacher asked the students to look at the stickers as those stickers have a
particular name that is factors of number in the box. Then teacher asked the
students what is the meaning of those. There are some idea came from students
one of them even see that if the two of numbered sticker multiplied then the
product will be the number in the box.
As for the prime numbers, teacher
give hints to the students that the number which has only 2 stickers. And students
have no difficulty to see which number is prime number and which one is not.
And they could see that factor of prime numbers consist of 1 and other number.
It is believed that students can
distinguish which number is prime and not. Even, the students understand that 1
is not prime and they also can mention numbers within 1-42 that are include in
prime numbers.
Unfortunately, the second activity
is not done yet. Because the time is ended before all the activities were done.
Conclusion
Most of the students can
distinguish a number whether prime number and not. However, for the numbers
higher than 42, it can be known yet. The evaluation should be assessing first
so that the result could be assured.
for the pdf version (english-indonesia) could be found here