GRADE 4 STEM EXPERIENCE ACTIVITIES

AIR PURIFIER

LESSON INFORMATION

1. OBJECTIVES

• Present the role of air purifiers
• Explain in a simple way the operation of the electric fan part in an air purifier

• Propose an air purifier product idea using a technical assembly kit
• Assemble the air purifier model
• Share about your group's products and express your feelings about the products of your groups

• Cooperate with group members when performing learning tasks

2. TEACHING AIDS

1. Teacher preparation

III. TEACHING ACTIVITIES

1. Activity 1: Introduction (Identify the problem) - 10 minutes

1.1. Warm up - 4 minutes

• Watch the video and discuss:

• Questions - Group discussion:

1. What is the environment around the main character like?

A: Air pollution

2. While in such an environment, what happened to the main character?

                        A: The main character had red eyes, sneezing,...

3. How did the main character handle it?

A: Wear a mask, wash your hands

• Linh video: situational videos

1.2. Identify the problem - 5 minutes

• Discussion:

• Situation - personal discussion: Next to An's house, he opened a wood workshop. Every day, there is a lot of dust in An's house. That's why sometimes youAn often cough. Is there any way to help An filter dust in the family?
• Situation link: https://drive.google.com/file/d/1QTo4RpDYJnrH29R9_cjm6-woueYBlvEk/view?resourcekey

A: An needs to wear a mask, buy an air purifier... The optimal solution is to buy an air purifier because An cannot always wear a mask.

• The teacher poses the problem: The air environment around us is increasingly polluted by dust and smoke from industrial parks, factories and enterprises. This will cause respiratory diseases: cough,... So how to limit the effects of fine dust on human health? Air purifiers are a reliable solution to bring clean air to our homes.

1.3. Assign tasks (1 minute)

• Product:Air purifier model using technical assembly
• Description: When the switch in the power box is turned on, the air purifier's fan blade will rotate. From there, dust will be sucked into the air purifier through the filter membrane
• Product criteria

2. Activity 2: Forming new knowledge (Researching background knowledge)

 2.1. Learn about air purifiers - 25 minutes

• Content 1: The role of air purifiers - 15 minutes

• Watch the video and discuss:

• Question: Describe the role of air purifiers?
• Linh video:https://www.youtube.com/watch?v=cD4g20_86aA

A: Role of air purifier: Removes dirt, absorbs odors, creates clean air

• Teacher concludes 1: Clean air is not only important, it is necessary for all of us. However, air quality is a social problem due to the effects of air pollution. The room environment or clean air can still be filled with invisible dust and dirt and can sometimes be detrimental to our health. Air purifiers will help us suck, filter and remove dust in the air.

• Content 2: Parts of the air purifier - 10 minutest

• Study sheet number 1

• How it works: Work in groups and fill out study sheet number 1
• Time: 5 minutes

TL:

• Teacher concludes 2:Basically, most air purifiers today are made up of 3 main parts: frame, fan, filter. Each department will have its own role

2.2. Learn about how the fan part of an air purifier works - 15 minutes

• Challenge - group activity:

1. Challenge 1: Use a hair dryer to blow shredded paper away from the dryer
2. Challenge 2: Use a hair dryer to suck scraps of paper closer to the dryer

• Equipment needed to prepare for the challenge

• Students in each group take turns using the dryer to perform the challenge. Execution time is 2 minutes

** Teachers will assist students in plugging in the power cord

• The teacher will call students to perform in front of the class

• Teacher leads: So if we want the pieces of paper to be sucked into the dryer, we must create a fan blade in the suction direction. Similarly, in order for dust particles to be sucked into the air purifier, we must also assemble fan blades to create suction force.

• Operating principle of the fan blade in the air purifier

• Introducing the operating principle: When the fan rotates, it creates suction. Small objects such as dust will be sucked in by the air flow.

• The teacher introduces how to create a fan blade with suction power

1. Method 1: Just change the direction of rotation of the fan blade and we can create a fan blade that rotates in the suction direction
2. Method 2: Install the fan in the opposite direction but keep the original rotation direction

• Group discussion question: Please list the devices that have suction power?

A: Vacuum cleaner, kitchen hood

• Teacher concludes: The exhaust fan part plays the role of sucking dust particles inside the machine.

2.3. Explore electric motors - 20 minutes

• Teacher leads: Did you know that the air purifier has a fan part? Do you know why those propellers can run? Well, that's because the air purifier has a power inside, which is the fan motor, kids.

** This motor will be attached to the fan rotating propeller.

• You see, in order for the fan to work, one must plug it in or install a battery, right? It is they who power the enginethere children. The same goes for the engine you just introduced. We need to provide energy for the new engine and equipment to operate.
• Introducing the motor and power box in the technical assembly

• Teacher guides students to install batteries into the power box (Quantity: 6 batteries)
• Teacher guides students to connect the motor and power box
• Students practice according to the teacher's instructions

• Challenge 1: Use the pieces from the engineering kit to assemble an electric fan

3. Activity 3: Practice assembling an electric fan using the technical assembly kit

3.1. Proposing and choosing solutions - 10 minutes

• Discussion:

• Questions - Group discussion

1. What model are you planning to build?
2. How many parts does an air purifier consist of? That's the other part?
3. What is the frame of the air purifier made of? Do you have any ideas about the shape of the machine's frame?
4. Air purifiers have an important part: the filter. Please choose the material to make the filter membrane?

• Product: Air purifier modelUse the technical assembly kit

• The teacher divides the class into groups of about 4 - 5 students/group in random arrangement or in groups.
• Students observe the model and come up with improvement ideas

3.2. Prototype fabrication, testing - 40 minutes

• Students assemble air purifier models in groups - 25 minutes

• Instruct: Assembly instructions

• Experiment:

• Compare with product criteria (evaluation form)
• Case 1: Press the button on the power box but the fan does not run
• Case 2: The frame is loose, pieces fall out when the fan runs
• Case 3: If the air purifier's legs are too low, when the fan blade rotates, the fan blade will touch the table
• Case 4: The fan's wind power is not strong

• Note:

• If you press the button on the power box and the fan does not run, check the number of batteries and how to install the batteries in the power box.
• If the frame is loose and pieces fall out when the fan runs, add pegs to secure the pieces.
• If when the propeller rotates, the propeller touches the table, then assemble more pieces to the bottom.
• If the fan's wind power is not strong, try installing the fan blades with different materials

3.3. Share, discuss, adjust - 20 minutes

• Self-assessment of products: Students use self-assessment sheets to evaluate assigned groups
• Product sharing:

• Product name, how it works
• The role of air purifiers
• Difficulties during assembly
• Orientation for product development and adjustment

• The teacher summarizes the activity:

• Praise groups that actively participate in activities and encourage groups that are not doing well
• Comments and summary on the topic

IV. Appendix

1. Time allocation

2. Study sheet

3. Evaluation form

4. Product illustration