Using the Problem-Based Learning in STEM Teaching About Bamboo Toothpick Houses

In Vietnam, there are currently stable and comprehensive innovations in the field of education. Educational scientists have shifted from knowledge-focused teaching to competency teaching. Since then, there have been more new research directions in teaching than in the past, such as integrated teaching, practical application of mathematics and STEM teaching, etc. In these directions, STEM teaching is a new and broad topic. In particular, there are many teaching methods used in STEM teaching. Some people use project teaching, some use discovery teaching, and some others use cooperative teaching methods. Through the research process, we found that STEM is an integrated area, so we should choose one of the most appropriate ways to approach it. That is a problem-based learning method. How does STEM teaching work with problem-based learning? To illustrate this STEM teaching work, we will use the design and implementation of the model of a bamboo toothpick house at Ho Chi Minh City International College.


Introduction
The technology revolution 4.0 has been happening fast based on the integration of many science and technology fields together. From digital connectivity to the Internet of Things artificial intelligence, nanotechnology, biotechnology, nanomaterials to self-driving cars, the world, including Vietnam, has wholly changed production and consumption. The Vietnamese Government is aware of the opportunities and limitations that the technology revolution 4.0 brings. Vietnam is currently taking shortcuts and welcoming advanced technologies in the world. Not only does Vietnam compete with one country or a group of countries, but it also competes globally. To compete in such a large playing field, it is nothing more than to promote further the field of science and technology, specifically here in the area of STEM. STEM stands for S: Science; T: Technology; E: Engineering and M: Math. STEM education equips learners with applied knowledge, enhances their ability to detect, solve problems, and develop creative competency. In Vietnam, there are currently robust and comprehensive innovations in the field of education. We found that STEM is an integrated area, so we should choose one of the most appropriate methods to approach it. That is a problem-based learning method. How does STEM teaching work with problem-based learning? To illustrate this STEM teaching work, we will use the design and implementation of the model of a bamboo toothpick house.
STEM education makes students realize that the sciences are not academic (it means that they have not any applications in real-world), but useful and worth learning. However, in Vietnam, the STEM field is entirely new. They mainly train teachers in the academic direction, so it is challenging to explore STEM-oriented teaching. Vietnam has not had any teachers who have been well trained in STEM and have graduated to serve to teach. Therefore, STEM education is inherently more difficult. more interested in learning STEM. Allen et al. discussed the quality of the STEM program, the relationship between the quality and output of college graduates in the United States. Hallström and Schonborn (2019) think that, when studying STEM, the integration of subjects must go along with maintaining the integrity of the issues. STEM is the bridge between theory and practice. Kurup et al. (2019) said that STEM education should start in elementary schools and should actively involve young people in their future. To create a generation of interest and skills in STEM, teachers should get students to work together in an integrated approach. Teachers play an essential role in STEM education. Teachers both play the role of instructor and act as learners with students. Margot and Kettler (2019) also agreed with Kurup et al. (2019) when considering STEM teaching schools. It is important to train teachers who are both excellent at pedagogical methods and professional knowledge. Teachers play an essential role in the talent development process, helping students develop practical skills in STEM teaching. Meanwhile, Omkin et al. (2019) wrote, when teaching STEM, it is necessary to be learner-centered, fostering, and developing positive thinking for students. Seyranian et al. (2018) studied gender and found that there is a big gap between men and women in STEM teaching. Female students are often less than male students in STEM-related professions. Manly et al. (2018) also stated that gender influences student learning at universities. Typically, female students in non-STEM schools are more likely to graduate than female students enrolled in STEM schools.
In Vietnam, some domestic researchers specializing in STEM research have also initially achieved specific results. Nguyen et al. (2017) devised a process of designing STEM education topics, including five steps: Practical issues → STEM concept ideas → Identify STEM knowledge to solve → Define STEM topic goals → Develop STEM topic-oriented questionnaires. The authors also use project-based teaching as the only teaching method in STEM education. Le (2017) introduced a 5-step process of developing STEM topics: Select specific content in the subject → Connect with products and items in practice → Application analysis → Point out relevant knowledge in issues in the field of STEM → Topic formation. Tran et al. (2018) dealt with the interaction between fields in STEM education and the process of designing STEM education topics in teaching biology with six steps as follows. First, select STEM education topics. Second, identify the goals of the STEM education topic. Third, identify issues to be addressed in the STEM education topic. Fourth, identify specific problems to be used to solve problems in STEM topics. Fifth, design activities. Finally, design criteria and testing tools, student assessment, etc.
Many authors have studied about problem-based learning. Nguyen and Tran (2019) offered a process of problem-based learning as well as illustrative examples of electrical diagrams. The authors also point out the advantages and disadvantages of problem-based learning in teaching students in technical schools. Ho (2017) presented a survey that the method of problem-based learning helps students in many ways. It will help them be active in learning, form the need to solve learning tasks, stimulate curiosity, be passionate about exploring science, make students motivated to develop, and foster creativity, collaboration, and critical ability. Hmelo-Silver (2004) provided the cycle table of problem-based learning cycle as well as comparing project-based teaching and problem-solving teaching. Strobel and Van Barneveld (2009) mentioned some perspectives on problem-based learning and how it helps, etc.
Although there have been many pieces of research on STEM and problem-based learning, there have not been any research projects on problem-based learning on STEM bamboo toothpick houses. Therefore, in this article, we will show how to use the method of problem-based learning in STEM teaching on the topic of designing, implementing, and lighting electricity for the model of bamboo toothpick houses in Vietnam.
We now go to problem-based learning, the role of STEM teaching in schools, the interaction between areas of STEM teaching, and the process for problem-based learning of STEM topic problems.

Problem-Based Learning Method
There are many views on problem-based learning. According to Nguyen (2004), in problem-based learning, teachers create problem-solving situations, tell students to detect problems, act voluntarily, positively, proactively and creatively to solve the issues and thereby build knowledge, train skills, and achieve other learning goals. Pham (2011) wrote that problem-solving methods are teaching methods in which teachers create problem-solving situations and students through problem-solving learning activities, create new knowledge, train skills, and achieve teaching goals. A problematic situation is one that evokes students with theoretical or practical difficulties that they feel are capable of overcoming, but not immediately but undergoing a positive process of thinking, working to transform objects, or adjusting existing knowledge.
The role of STEM teaching in schools now is significant. The education of Vietnam interests in this topic very ies.ccsenet.org International Education Studies Vol. 13, No. 12;2020 72 much. Nguyen et al. (2018) said that STEM teaching would bring many benefits. Specifically:

The Role of STEM Teaching in Schools
Ensuring comprehensive education: Deploying STEM education in schools, besides subjects such as Math and Science, Technology, and Engineering fields, will also be considered and invested in all aspects (teachers, programs, facilities).
Increasing interest in learning STEM subjects: Learning projects in STEM education aim to apply interdisciplinary knowledge to solve practical problems. Students act, experience, and see the meaning of wisdom in their life, thereby increasing their interest in learning.
Forming and developing competency and quality for students: When implementing STEM learning projects, students cooperate proactively and self-implement the learning tasks; be familiar with activities of a scientific research nature. The activities, as mentioned above, contribute positively to the formation and development of qualities and competencies for students.
Connecting schools with the community: To ensure effective implementation of STEM education, the general education institution usually connects with local vocational schools and universities to exploit human resources and facilities to implement STEM educational activities. Besides, STEM education in high schools also aims to solve typical local issues.
Career guidance and streaming: Well-organized STEM education in high school, students will experience in STEM fields, assess their suitability, aptitude, and interests in careers in the field of STEM. It is also a way to attract students to study, select professions in the field of STEM, which is in high demand for human resources in the 4th industrial revolution.
This part refers to the integrated things in STEM teaching.

Interaction Between Areas of STEM Teaching
According to Thornburg (2008) and Tran et al. (2018), the fields of science, technology, engineering, and mathematics are closely related to STEM teaching. Math and technology are used in scientific and technical research to help people explore and improve the world. In contrast, Science and Technology promote the advancement of Mathematics and Technology. The difference between Science and Technology shows the purpose and method of implementation. The goal of science is to "search" for the study of things and natural phenomena, and technology is about the "implementation" to design and manufacture objects for the advancement of humanity. Scientists use a "Scientific Method" to explore nature and make assumptions and verifications that are formed and developed for students at multiple grade levels. To design and manufacture, engineering needs to build and develop for students' creativity and innovation, which are essential attributes in the field of engineering but difficult to quantify and take a long time to form. A prolonged learning environment stimulates creativity. This difference is relative because science also requires creativity, and engineering studies also need scientific methods. Therefore, the approach to STEM education must be an interdisciplinary approach to create a harmonious combination between the fields of Science, Technology, Engineering, and Mathematics to help students experience reality to explore knowledge and create meaningful products.
We now go to the process of problem-based learning of STEM teaching. This process includes eight steps.

The Process for Problem-Based Learning of STEM Topic Problems
Step 1. Detecting STEM topics STEM topics for teaching can come from teachers, students, or external factors. During the teaching process, if teachers find the STEM topics interesting, practical, or those topics have a pedagogical effect, stimulate exploration, teachers can assign tasks to students to design and learn those STEM topics. Teachers do not have to impose students to work the STEM topics, but teachers should inspire them to be attracted to the subject given. Teachers must turn external learning motivation into a student's internal learning motivation.
Step 2. Identify problem-based learning methods that are appropriate on STEM topics Depending on the students' qualifications, competence, and attitudes, teachers have appropriate forms of problem-based learning. If the student is good and patient, the teacher should use the gradually permeable teaching method (Osmosis). Students are "immersed" in the environment on the subject of STEM to address. Students are encouraged to solve the STEM topic with all their efforts, not being pressured by time, not afraid to fail. They are allowed to choose how to do and complete their STEM topics.
If students are weak, they will receive a lot of support from teachers. Memorization teaching should be applied to the students. STEM topic-solving tasks are broken down by teachers into small learning doses that students can comfortably handle. Students then memorize and summarize the jobs they have completed.
If the students are outward-oriented, we should assign them to work in groups. They are allowed to discuss and argue their decisions with their peers, thus finding the best way to solve STEM topics.
If the class has many students with different minds and strengths, the teacher can divide the teaching of STEM into doses that are appropriate to the tendency of each group of students or each student. Then sum up the results together. This teaching method is a reflection method. This teaching method assumes that students learn by working and reflecting on what they do. Students are encouraged to restate how to solve their problems.
Step 3. Select materials and learning media in teaching STEM topics Teachers ask students to prepare materials for STEM learning. Where do these materials come from? Where to buy? What are the accompanying tools? What is the learning media to prepare?
Step 4. Determine the knowledge of STEM students need to prepare Teachers hand over STEM learning materials for students to prepare in advance. What is the basic knowledge of STEM topics? What is the knowledge to learn about science, technology, engineering, and math? What knowledge can be read and understood? What knowledge goes beyond the program to receive to complete STEM products?
Step 5. Set goals when teaching STEM topics Teachers should know the knowledge, skills, attitudes, and competencies that students achieve after completing the STEM product. In terms of knowledge, teachers should classify into three categories. The first type is the knowledge that students have learned; the second type is new knowledge, but students can read and understand themselves; the third type is new knowledge, but students do not understand. It is outside the student's curriculum. This type of knowledge students should accept the results to apply. When teaching STEM lessons, the teacher needs to determine how well the students are performing, so the requirement of a student's training will be met. Students with weak and moderate academic performance should focus on fostering knowledge, understanding, and application activities; Students who have good and excellent academic ability promote analytical, evaluating, and creative teaching activities.
In terms of skills, teachers need to identify which skills students will learn through the STEM topic. What are thinking skills? What are the scientific skills? What are the learning skills?
In terms of attitude, teachers ask students to be positive, passionate about science, conscious of environmental protection, conscious of recycling waste products in life. In studying, they should never stop learning. If they decide to do something, they should work till the end.
In terms of competency, teachers focus on training some key competencies such as problem-solving, creative thinking, cooperative, and artistic skills.
Step 6. Design lessons of STEM topic After defining the lesson objectives, the teacher should write a detailed lesson plan on how to teach STEM. The primary teaching method here is the problem-based learning method. The teacher creates a detailed questionnaire that corresponds to the task that the student needs to complete in STEM learning. What is the question when a student is about to start studying? How to design STEM products? How to perfect the STEM product? What is the way to use learning media in the teaching process? Do we need dosage more or less? For how well the student learns, the question must correspond to the student's level of awareness. The design of STEM products assigned to each child or group motivates them to collaborate and know how to work collectively.
Step 7. Design a toolkit, criteria for testing and evaluating students To evaluate students' products and cooperation in learning activities (if any), teachers need to design learning assessment sheets, distribute appropriate scores for each indicator. Design evaluation sheets for group activities, build evaluation criteria, distribute points appropriately for each sign, and complete the evaluation form.
Step 8. Find out more about the STEM topic From teaching STEM topics, teachers encourage students to learn more about other STEM products with similar design methods, benefits of studying STEM topics, difficulties that they need to overcome. Students can dig deep, develop more about the features of the STEM products they have done as well as draw the results achieved after learning. ies.ccsenet.

Results
Step 1  Step 5 Vol. 13, No. 12;2020 Promoting creativity and logical thinking when drawing the plan manually according to ideas and implementing models; Critical thinking and problem-solving skills

Attitude
Having a spirit of cooperation and a sense of responsibility; Be careful and meticulous in the process of implementing individual details. -Using pencils, rulers, A4 paper (A3), you can use a computer to implement the design concept.
-Use tools such as pliers, scissors to make the model.

ENGINEERING (E)
-Students understand the process of model implementation as well as the process of building a home.
-Directly generate ideas, directly implement models from analysis, synthesis and combination to balance physical, artistic and technological factors, etc.

MATHEMATICS (M)
Calculate the rate, the balance between the objects of the model.
Calculate and measure models from plans to reality.
Step 6. Design a lesson for STEM topics + Duration: time for implementation of 20 periods/class or more (30 to 40 students) + Location: Classroom or practice room of the school or student's house. + Implementation process: -Teachers hand out evaluation sheets; product reviews, performance assessments for students.
-Based on the learning topic and suggestions of the teacher, students propose and promote the tasks to be performed.
-Students assign tasks to each member of the group, the time of each person, the method of implementation and the means to produce the final product, a bamboo toothpick house.
-Design PowerPoint slides to report the work of the group. ies.ccsenet.
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The topic " students. T see the app Step 8 Vol. 13, No. 12;2020 Step 8.6. Design a STEM topic lesson + Duration: time for implementation of 20 periods/class or more (30 to 40 students) + Location: Classroom/practice room of the school or student's house. + Implementation process: -Teachers hand out evaluation sheets, product reviews, and performance assessments for students.
-Based on the learning topic and suggestions of the teacher, the student proposes and promotes the tasks to perform.
-Students assign functions to each member of the group, the time of each person, the method of implementation, the means to produce the final product, which is electric lighting, the model of a bamboo toothpick house.
-Design PowerPoint slides to report the work of the group.
Step 8.6.2. Implementation and construction of STEM products (10 periods Vol. 13, No. 12;2020 Step 8.7. Design toolkit, test criteria, and student assessment In addition to the set of criteria for evaluating group and individual activities, we also set up a set of standards for evaluating product design and lighting of a bamboo toothpick house model as follows: Do not know how to read some places on the drawing.
Students have failed to complete the electrical design product according to the drawing, and they are unable to read the drawing.

Creativity
The product is innovative, has a high practical application.
The product is innovative but still a bit awkward.
The product is molded and not flexible.

Discussion
In Vietnam, no other plant is as abundant and useful as bamboo. They can process bamboo into high-class handicraft products, supply to domestic and foreign markets. Teaching students the topic of STEM-related to bamboo is very helpful. Students will find bamboos more useful. From the design and implementation of the model of a bamboo toothpick house, students will initially get acquainted with construction drawings, house models, which will help in finding a career that suits them. In teaching about the design and implementation of the model of a bamboo toothpick house, the method of problem-based learning is one of the most appropriate teaching methods. This method helps teachers to raise problems for students, help students solve problems, and deepen problems. Also, the practice of problem-based learning helps students work together to perfect the product of a bamboo toothpick house model. After completing the model of a bamboo toothpick house, students think about lighting it up. This approach is a creative way that needs to be encouraged for replication when teaching STEM.