Let's Measure Height

Heny Kurnia, S. Pd, SMP 4 Tanjungbalai

STICKS of wood can help in learning mathematics. I asked the students to bring the old handles of brooms, which were no longer being used. Otherwise straight wooden sticks would do instead. The length of the wood must not exceed 200 cm, so that students do not have difficulty carrying it. Other supporting media, such as measuring apparatus and shovels were all available at the school. I told the students that we can calculate the height of a building without climbing up it. I took the students out of class. For forty minutes, students were asked to follow the steps described in the work sheet. The students planted two different lengths of wood adjacent to each other. Each piece of wood cast a shadow. The students measure the length of the shadow of the wood. From there, they were asked to make a comparison between the height of the wood and length of the shadow. After that, for 20 minutes the students presented the results of group work. After the group presentation was finished, I provide reinforcement to the students for five minutes.

Two poles of wood were placed parallel in the ground. Then the students measured and compared the height of the poles and length of the shadows. Then they calculated the height of a building using the ratio they had found.

I explained the method of measuring height. Then the students were asked to draw their own conclusions and write a reflective journal. The lesson went smoothly and on time. I was surprised when the students said they could calculate the height of poles and high buildings in their neighborhood. The proof - they can measure the height of the school flagpole.

Students Observe Transformation of Energy in Photosynthesis Experiment

"Why do you prefer to sit near the school shop where there are trees rather than sitting around the edge of the school yard?" Asked Ibu Lili began the process of learning science in class VIII, SMP 8, Bogor, West Java. Each of the students gave their various reasons. Teachers guided them in their reasoning so that they reasoned, "because there are plants that produce oxygen."

"What are the benefits of oxygen for our bodies?" Asked Ibu Dwi who was team teaching with Ibu Lili. Students gave various explanations. Ibu Dwi then explain the purpose of the lesson: "You've learned that, in order to obtain food, plants perform photosynthesis. Today we will discuss what is produced by plants during photosynthesis other than food." The students in groups of four did an experiment on photosynthesis by assembling their apparatus. They observed that gas is formed as a result of photosynthesis.

They also noticed three factors that influence the process of photosynthesis. They discussed in their groups to answer questions on the worksheet based on their observations. The teachers went around from group to group to guide the students and ask them questions. Each group prepared a report on the experiment which included the aims of the experiment, equipment and materials used, way of working, observations and data analysis and conclusions. The reports were written on large paper and then displayed on the classroom walls.

Each group made a presentation of the results of their discussions in turn. The apparatus used in the experiment was shown during the presentations. After the presentations, teachers and students drew conclusions from the experiment. The teachers gave special praise to the best-performing group. Students were then encouraged to conduct their own experiments at home to get a better understanding of other factors in photosynthesis.