Unfortunately, teaching science has become text-book based. Project Based Learning (PBL) and Inquiry based learning (IBL) are approaches to science teaching focusing on understanding the world by questioning, investigating, observing and explaining the order of the world around us. Some teachers may find it challenging to identify a project, but one cannot deny the learning that students experience through projects. Through engaging in projects, students can begin to understand the nature of science.
A few months back I gave a project to my students. I made a dengue monitoring team. The team monitored the pond waters of the Institute and observed if there was any evidence of Dengue mosquito larvae.
Students took water samples from the ponds. The samples were analysed, first with a magnifying glass (in the field) and then with a compound microscope in the science laboratory. The project concluded that the collected water samples did not have any evidence of Dengue Larvae. The students learnt different skills such as observation, data collection, prediction, and inferring etc. They also learnt to make microscopic slides. They also learnt to use different instrumentation such as microscope and pH meter. They extended the project by monitoring the pH value of the water and also collected data on different types of flora and fauna in and around the pond.
Let’s bring theory to practice and make science more meaningful for our students.
In the science week at AIE, we had an opportunity to interact with school science teachers on a number of different workshops. Out of five workshops I enjoyed conducting the workshop entitled ‘Kitchen Chemistry’ the most. The aim of this workshop was to help teachers explore how to use everyday kitchen items to conduct science experiments. During the workshop participants identified major food groups and the additives they contain. They performed simple experiments using kitchen ingredients and identified different physical and chemical changes taking place during in the kitchen.
The topic was introduced by an activity in which I prepared tea and a sandwich in front of the class, discussing how these are made up of number of chemical compounds. Tea is a mixture of caffeine, water, sugar and milk. Bread is made from three main ingredients: water, grains and leavener (also called raising agent). Making bread from yeast is an aerobic reaction. Cooked bread has a spongy texture due to carbon dioxide. We also discussed that there are many food items that contain additives which are mainly artificial in the form of colouring agents, flavouring agents, emulsifiers, stabilizers, preservatives, gelling and glazing agents.
The groups made jelly and sandwiches with mayonnaise and boiled eggs. When eggs are cooked they become firmer. This is because cooking changes the shape of the amino acid chains in the egg. This is called ‘denaturing’. Mayonnaise is an emulsion. It does not separate when it is left to stand. Mayonnaise is made using egg yolk. This contains lecithin, which is a natural emulsifier. Jelly is formed due to pectin which is a carbohydrate found in fruits. When sugar is added, the pectin in fruit precipitates out and forms insoluble fibres. We also discussed different chemical compounds which are responsible for the colours of different vegetables - for instance: orange is ?- and ?-carotene; red is lycopene; purple is anthocyanins; yellow is flavonoids; yellow-green is lutein.
The workshop ended with lots of laughter - the participants learnt and had fun at the same time.
During the AIE summer “Kids’ University” we explored the use of microscopes in one of the science sessions. It was one of the best sessions. The sight of the microscopes made them really excited (the felt like real scientists!) and the kids started exploring the use of the microscopes which raised many questions. They asked how a microscope works and what they can see using it.
I showed them how to adjust the microscope. The children prepared onion cell slides for the first time ever. They were surprised to see the layers of hexagonal cells stained blue with methylene blue dye arranged in an orderly manner. Even the nuclei were clearly visible. They learnt to change the magnification powers. They learnt to use course and fine adjustments. They adjusted the mirror to focus the light on the slide.
Later the students prepared slides of samples of moss and fungus. They enjoyed observing different samples under the microscopes. It was a great learning experience for them as well as for me. Even the small kids of Grade-2 learnt to prepare slides and operated the microscopes and recorded their observations on the worksheets.
This reinforced for me the value of using hands-on and minds-on approaches for teaching science to promote students interest in this subject.
WHAT IS STEM?
Knowledge expands with great rapidity. We are surrounded by the wonders of technology. To prepare student-teachers for the challenging future this represents, it is important that we equip them with wide-ranging skills. The 21st Century teacher needs to look critically at what and how students are acquiring these skills. STEM (Science, Technology, Engineering and Mathematics) is a well-known and well-practiced idea in many countries, here in Pakistan there is still scope for doing more.
I shared the idea of combining disciplines (i.e. STEM) with my student-teachers. STEM is about integrated learning, bring together opportunities for students to develop problem-solving skills, productive team work, decision-making skills, whilst engaging students in innovative projects, making connections with real world problems and creative solutions.
The student-teachers decided to work on 3 different projects. One group made an anemometer - an instrument that helps to measure air speed. Another group designed a conveyor belt – to move things from one place to another. The third group designed a hand-biometric system.
The students worked enthusiastically and enjoyed the projects. 21st Century teachers should always try to bring creativity and innovation to their lessons - scientific literacy is the ultimate goal.