2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
2 nd Observation Report: Learning Design of Relationship Among Weight Units at Grade 3A SD Negeri 117 Palembang by: Ahmad Wachidul Kohar 1) Fanni Fatoni 2) Wisnu Siwi Satiti 3)
A. Introduction Concepts of measurement in mathematics curriculum at elementary school have close relationship with activity of comparing object measured and standard measurement. Student’s experiences in measuring object could help to develop their skills in measurement activity. One of the experiences which can be taught to the students is introducing gauge such as gauge for weight unit, ruler for length unit, and measuring cup for volume unit. By knowing and trying the use of those gauges directly, the students will not only understand practical application of calculation skill which has been learned, but also bring benefit to the quality of their comprehension of measuring skills and its relationship with other studies like science which need this kind of skill more. Relating to PMRI (Indonesian Realistic Mathematics Education), the introduction of gauge could be a context to start teaching the relationship among weight units. The benefit of this context in the beginning of lesson is like what Wijaya (2011) said that context will be able to increase student’s motivation and attraction in learning mathematics. This is because of student’s attraction to create relationship between new things which are taught and their daily life. Hence, we (Kohar, Fanni, and Siwi) together with teacher at class 3A SD Negeri 117 Palembang create a collaboration to design learning using PMRI approach on material of the relationship among weight units by using needle scale. The description of how the teacher and we designed learning, implemented that design, and analyzed the result of teaching experiment is explained at part of learning design.
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2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
B. Purpose of Observation The purpose of this learning design and observation are to: 1. describe the learning of the relationship among weight units (kilos, gram, and ounce) by using PMRI approach at grade 3A SD Negeri 117 Palembang, 2. build experience to the observers to design and cunduct learning using PMRI approach on material of the relationship among weight units. C. Learning Design The material taught in this learning is the relationship among weight unit, which focus on the relationship among kilos, gram, and ounce. This learning was carried out at class 5A SDN 117 Palembang. The steps are preliminary design (curriculum analysis, the determination of indicators and learning objectives), continued with teaching experiment and retrospective analysis (reflection of learning) which will be described as follows. 1. Preliminary Design In this activity, we analyzed curriculum with the purpose of matching designed learning with the mathematics curriculum for Grade 3 of elementary school. The analysis comprises the determination of material which will be taught, learning objectives, and learning indicators. Based on information from teacher (Mrs. Fatmawati), the material about relationship among weight units is taught after the topic of money. The material could be taught and kinds of gauges also be introduced simultaneously. Standard competence and basic competence which underlies the compiling of lesson plan respectively is using time measurement, length, and weight in problem solving and understand the relationship among time units, length units, and weight units. From the basic competence, we formulated learning objectives and learning indicators. Because the focus of this learning is to convert unit from kilos to gram, ounce to gram, and kilos to ounce, the learning objectives are that students could estimate the weight of given thing that is more than, less than, or equal to 1 kilo by using a gauge, and also students could conclude the relationship between kilosgram, gram-ounce, kilos-ounce using their own words.
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2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
After determining learning objectives and indicators, the next activity is to design the content of learning activity which will be held. We chose the context of gauge for weight as starting point to teach the relationship among kilos, ounce, and gram. This context was chosen based on Mrs. Fatmawati’s suggestion because this gauge is often met by students in their daily life. Moreover, students will be experienced in using gauge directly. Based on our pre observation result, students seemed to be active in following learning when the teacher asked them to give feed-back such as waiting the turn to demonstrate the answers on white board. This situation inspired us to design learning that involves students more deeply in both when they have presentation and work in group (interactivity). Hopefully, it will bring students to their own understanding problem given by constructing their own finding about mathematics concept/skill (student’s contribution). To find the relationship among kilos, gram, and ounce, students are desired to use the concept/knowledge from other/previous topics (intertwining of learning strands) like addition and multiplication, such as how many package of sand (10 gram) which are needed to build a package of sand with the weight of 1 ounce. In relating with the process of mathematizing which is likely built by students through model (use of model), we arrange ice berg of material of the relationship weight units.
Figure 1. Ice berg of material of the relationship weight units.
Based on ice berg from figure above, measuring instrument scales and daily goods often be found by students are the context to start learning.
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2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
Meanwhile, as a model of in this learning, students are asked to measure directly some goods and package of sand in any size by using scales, then direct students to transcribe data which they acquire into tables served as a model for. Henceforward, students are expected to find the conversion of kilos. to grams, ounces to grams, and kilos. to ounces which is the form mathematics formal from the relationship among a series of activities be in groups.
Figure 2. Sand and scale as model of in learning
After composing design of learning, we transfer that design into the draft form of lesson plan and LKK (Sheets Group Activity) which was consulted to Mrs. Fatmawati and Mrs. Yusniar (teacher partner who last year cooperated with senior) before the learning dated on November 7th 2012. From the consultation, we obtained some advice about lesson plan which should have been written in the draft of thematic (existing links with other subjects like bahasa Indonesia, natural science, or social class). Even though learning design we have already arranged contained those link elements, according to Mrs. Fatmawati, especially for bottom classes, lesson plan should be assembled using format of thematic in order to be obviously seen that there is connectedness among subjects learning. Furthermore, actually we plan to use type of sitting scales as media of learning. But, since until the learning time came, we initiated to use needle scale to substitute sitting scale. 2. Teaching Experiment Learning activities were carried out on Wednesday, November 7, 2012. Mrs. Fatmawati acted as teacher, while we acted as observers of student’s activity and helped teacher to customize classes when learning took place. Learning activities was started by reminding previous material about money through a game with the use of the media colored pipette. The rule
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2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
was that blue pipettes show thousands, yellow pipettes show hundreds and red pipettes show tens. The students sent to transcribe notation exact money when the teacher holding some combination of the three types of pipette said. For example, 3 blue pipettes, 4 yellow pipettes, and 5 red pipettes show money of Rp 3.450,00. Students looked very enthusiastic to follow this game, which was indicated by many of whom raised their hands to get a chance to transcribe a notation exact money on the board, even though there was a student who still was wrong to wrote it down. The activity continued to start teaching the relationship the unit of weight. The teacher asked the students about the kinds of weigh scales and the place where they usually found. Some students answered kind of scales is found in hospital, a house, puskesmas (resident hospital), and posyandu (for babies), while needle scales are often found on the market. Asking and answering question session was held by teacher to insert the social lesson about social activity which is student’s daily life. Meanwhile, subject of Indonesia lesson on the topic of writing was slid when students wrote down names of places where scales can be found as indicated 2 following in a picture
Figure 3. Student’s answers of where scales can be found
Then the teacher explained how to use needle scales by weighing some of the packaging of goods with certain brands which have been prepared such as margarine, flour, and chocolate sprinkles for the bread. To ensure that the student has learned how to use the scales well, the teacher asked some students demonstrated how to weigh and see the size of the weight is directly implied by the needle scales. In addition, students are also required to sort three items that weighed just now starting from the most weight to the lightest. The students were able to order those items properly. However, when they were asked to state the reasons why flour was the most weight
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2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
and chocolate sprinkles was the lightest, they explained in different reason. There were students explaining that flour is the most numerous things while chocolate sprinkles was the fewest one. Activities continued by the grouping students to work on LKK to find connections among the units of kilos, grams and ounces. Each group consisted of 5 heterogeneous students. The teacher explained the steps of LKK in any type of activity that will be performed by students. The specified activity is activity 1: sorting the objects based on the size of the weight of the heaviest to lightest, activity 2: discovering relationships kilos and grams, activity 3: finding the relationship ounces and grams. It is important to know that in this case, one ounce is equivalent with 100 grams according to the standard used in Indonesia. After grouping students, activity 1 started by carrying out a series of weighing activity measuring 3 different types of packaged goods (1 kilo of flour, 200 grams of margarine, and 100 gram of chocolate sprinkles,). Since the number of existing scales was only 2 pieces, each group took turn to use the scales while the other groups who have not got a turn yet were asked to pay attention to the group who was weighing. After all the group weighing the goods, the activity continued by answering questions in activity 1 based on the results of weighing.
Figure 4. Weighing activity to order the goods based on their weight.
Initially, uncontrolled student’s activity took place in a group. There were students who were scrambling to become the leader of the group, there are always students protesting against his/her group, there's even a male students were urged to become leader of the group as all the other members in the group that there were female students. At the time of the activity, however, all students want to get put the goods which have been provided on the scales. In addition, when students were asked to weigh objects in
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2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
order to achieve a specific weight, some students even put all the weight on the scales and they didn't notice the weight indicated on the scale. Every student wanted to hold and demonstrated, whereas the availability of props was very limited. However, this situation can be resolved soon when we helped Mrs. Fatmawati to customize the students to write down the results of the activity 1 orderly. The following is the variety of student’s answers of activity 1.
Figure 5. Student’s answers in activity 1
From student’s answer, it is known that they could sort things provided properly. However, when students were asked to give reason why flour was the heaviest and chocolate was lightest, students had some different answers. Some reasonable reasons from students are that because flour weighed 1 kilo and chocolate sprinkles weighed 1 ounce. The next activity was the carrying out of activities 2. In this activity, Mrs. Fatmawati was replaced by one of us (Fanni). Activities 2 led the students to determine how many grams packing sand needed to obtain sand packs weighing 1 kilo. Packing sand provided was 100 g, 200 g, and 300 grams. Each group might chose any combination of these three types of packaging to be weighed with the needle scales. Here is a variation of student’s answer on the activity 2.
Figure 6. Variation of student’s answers on activity 2
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2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
Of some answers students above, it can be seen that there was different combination to acquire packaging sand with the weight of 1 kilo. However, at the start of lesson, some group still wrote wrong answers. Interestingly, they know the total that true but they wrong to write answer supposed to 1000 grams written 1000,00 grams. After carrying out activity 2, the teacher explained the activity 3: weighing some package of sand weighed of 10 gram to discover the relationship between ounce and gram. Since the students are accustomed to weighing objects like they did in the previous activities, in this occasion, they did not find any difficulties to find that 1 ounce is equivalent with 100 gram.
Figure 7. Students are discussing questions on activity 3
After discussing the questions on activity 3, students carried out presentation from some representatives of group. The teacher guided this activity by asking them to real aloud the result of each activity one by one. The teacher also asked the feed-back from other group. For activity 2,the student’s answer from all group can be seen as follows.
Figure 8. Student’s answers on activity 2 written on board
From the figure above, it can be seen that student’s answer is diverse. This is because when weighing activity, there was a possibility for each group to take the package of sand randomly. However, all the student’s answers were appropriate with expected answers, that say that 1 kilo = 1000
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2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
gram. The discussion continued to go to on until students together with teacher concluded the lesson. 3. Retrospective Analysis After learning activity finished, Mrs. Fatmawati and we carried out analyses retrospective with the purpose of reflecting and analyzing the process of learning which has been done and also compared the learning design and the facts which happened during learning activity. Overall, the learning activity was appropriate with lesson plan, although it took longer than we planned (90 minutes instead of 70 minutes). This obstacle happened because of the crowded class at the beginning of the lesson and at weighing activity so that the teacher needed to customize students to be calm down. Even, the teacher had an initiative to sing to make students focus on the learning for a while After discussing with Mrs. Fatmawati, we obtained information that students indeed are accustomed to scrambling stating their opinion when the teacher pose a question. It sometimes make the situation in the classroom crowded. Moreover, when students work in group, each of members is likely to touch whatever used as learning media. However, after the teacher explain some rules like giving a chance to only a student who raised a hand and discuss with the group before weighing the objects, the learning could be conducted well. This could be seen when the teacher guided students to present the group work result. The students seemed to orderly follow the rules like listening to the group presenting in front of the class and reveal another idea when the idea presented was different. According to our observation when students conducted activity 2, some groups seemed have difficulties to find the combination of sand package precisely so that they looked for another strategy to reduce or even add dosage of sand in order to make needle scale showed 1 kilo. One of their strategies was to count the lack of the package needed to form a package of sand with the weight of 1 kilo. For instance, if using 2 package of sand 300 grams, the needle showed 600 grams, then they only needed to add a few of package of 100 grams or 200 grams to get 1 kilo. We deliberately designed
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2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
this kind of activity to emerge student’s creativity to find out the precise combination of the package so that each of group will be likely had different answers. Another finding can be seen from student’s result on LKK. We found that five out of eight student’s answers on activity 2 stated that 1 kilo is equal to 1000,00 grams instead of 1000 grams. We supposed that they still be influenced with the way of writing right notation for currency which they learned before learning the material of relationship among weight units. Relating to the learning design we planned, the situation above represent two characteristics of PMRI which are expected to happen during the learning. They are student’s contribution shown by student’s much involvement to find out the relationship among kilos, gram, and ounce and interactivity shown by the existence of communication among students and between students and teacher, particularly during group discussion and group presentation. Meanwhile intertwining is shown by the student’s strategy to apply their skill of addition and multiplication to find out the relationship between kilos and gram. However, the characteristic of use of model which is shown by using needle scale as learning media, was not appropriate with our plan to use sitting scale (instead of needle scale). We argue that the unavailability of number shown in the sitting scale will probably pose students to think more creatively to choose the precise package in order to get the expected value. On the contrary, since there are some numbers representing the weight of object weighed, it is worried that students will probably only add/reduce the dosage of package to obtain the weight of 1 kilo without considering the real meaning of numbers shown in the scale. D. Conclusion Based on the design and the process of learning conducted at Grade 3A SDN 117 Palembang, we conclude some terms below. 1. Through the learning of the relationship among weight units using PMRI approach, the students were able to find out the relationship among kilos, 10
2nd Observation Report , SD N 117 Palembang, Sumatera Selatan
(IMPoMe4 2012)
gram, and ounce (1 kilo=1000 gram, 1 ounce=100 gram, and 1 kilo=10 ounce). 2. The use of scale is needed to be considered as the media to build student’s understanding about the relationship among weight units by considering the kind and the function of scales used.
References Pujiati. 2004. Pengukuran (disampaikan pada Diklat Instruktur Matematika SD jenjang Lanjut tanggal 6-9 Agustus 2004). Yogyakarta: PPPG Matematika. Wijaya, Ariyadi. 2011. Pendidikan Matematika Realistik. Yogyakarta: Graha Ilmu.
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