“From the concrete to the abstract; from the near to the far,” this is the first true principle of education. All children are born scientists. Children have boundless energy and being new to the world they are keen to figure out how the real world works. This they do by engaging with the real world – by doing real experiments. Experiments are best done with simple things – often throwaway stuff. Inexpensive stuff makes activity-based learning accessible to many more children – especially the poor. Simple everyday items and ordinary things can easily be fashioned into toys for science learning. Here are some examples of an innovative approach to science learning that is also easy on the environment. These examples will give you a feel that sophisticated science activities need not be expensive.
Here is a puzzling problem: Can you balance ten nails on the head of a vertical nail? You just need a dozen 10-cm long nails easily bought from a hardware store. Place one nail in a straight line away from you on a table. Now place 8 nails at right-angles to the first nail. Their heads should be alternating – one to the right, the other to the left. Place the last nail on top of the first nail. Then pick the assembly gently with both hands and perch it on the head of the vertical nail embedded in a wooden block. The nails will balance gracefully and you can safely rock them to-and-fro! See video.
What simpler material than clay! It is universally available and costs nothing. Make 4-clay balls of the same weight and size. Then transform each ball into a different shape – animal, cube, cup and a saucer. Ask your friend, “Which shape is heavier?” Each shape was made from a similar ball. So how can they have different weights? This will give children a good inkling about conservation of weight.
WHICH EMPTIES FIRST?
Take two similar plastic bottles. Remove their lids. Make two holes in each lid. Press fit a short stiff straw in one lid and a long straw in the other. The second hole in the lids will have similar short straws to let in the air. Glue the straws in place. Now fill both bottles fully with water; screw on the lids. Name the bottles – H1 and H2. Now ask your friends. “On inverting both bottles together which will empty out first – H1 or H2? Or will both empty at the same time?” Chances are that 90% will vote that both will empty out together. But, on inverting the bottles you will be in for a pleasant surprise. Bottle H2 will empty out first. H2 being longer its higher water column will exert more pressure at the bottom of straw H2 and so it will drain out first. See video.
WHICH HOLDS MORE?
Postcards in India measure 14-cm x 9-cm. Fold two postcards into cylinders by bringing their long and short edges together and then tape them. Ensure that the edges do not overlap. You will get a thin but tall (14-cm tall) cylinder. You will also get a fat, short cylinder (9-cm tall). Both cylinders will have the same surface area. Now, ask your friends: “Which cylinder will hold more sand?”
Most will say that both cylinders will hold the same amount of sand. But on testing they will be in for a surprise. Fill the thin, tall cylinder with sand to the top. Then slide the fat cylinder on the thin one. Finally shake the thin cylinder and remove it. This will enable you to compare their volumes. The fat one will be only 2/3 full! Why? The volume of a cylinder depends on the square of the radius and its height. As the fat cylinder has a larger radius, the square of the radius makes it a lot more capacious.
All children love playing with toys. During play they intuitively grasp the science behind the toy. Later on when they encounter the same science in their textbooks – it does not seem so overwhelming. The simple straw sprinkler incorporates it all. It costs little; can be made in a jiffy and is loads of fun. Poke a stiff broomstick in the middle of the straw. Make two equidistant half-cuts in the straw. Bend the arms in a triangle and tape them together. Place the sprinkler in a glass of water and spin the broomstick and water will sprinkle all over! Through this amazing toy children will concretely understand the invisible force of spin – the centrifugal force! See video.
Tie two strong cords on both ends of the cycle wheel’s axle. Lift the wheel with both strings and then ask a friend to spin the wheel. Then drop the left-hand string of the spinning wheel. The wheel will not fall. Instead, the spinning wheel will start rotating in the clockwise direction. However, on dropping the right-hand string the spinning wheel will start rotating in the anti-clock direction. The spinning wheel does not fall because of gyroscopic action.
At the heart of the Levitating pencil are six ferrite ring magnets. Four magnets are embedded in a rubber base. The magnet on the pencil near its pointed end attracts the two magnets below it (C attracts A and B) and is slightly behind A and B. The magnet near the blunt end of the pencil repels the two magnets below it (F repels D and E). This makes the pencil levitate – hang in the air. As there is very little friction, so on twirling, the pencil will keep spinning for a very long time. This low-cost science teaching aid will help children understand the working of Maglev Trains. See video.
The Touching Slate is based on a simple idea that wool sticks to Velcro. The slate is made by sticking Velcro strips on a stiff cardboard. The drawing pen is essentially a “fishing line” which dispenses wool. Blind children can draw their artwork on the Velcro slate. Later they can “feel” the drawing with their fingertips. The only thing to be bought is the Velcro. The rest of the material can be easily collected. India has thirteen million visually impaired people – the largest in the whole world. This low-cost slate is extensively used in Blind Schools throughout India.
Watch a video on making the Touching Slate.
SIMPLE ELECTRIC MOTOR
The Electric Motor is used in a dozen places at home – fan, cooler, fridge, mixy and washing machines etc. In school children simply mug up its theory. Rare is a child who ever makes a motor. Apart from a 1.5-volt torch battery you need a ferrite magnet, two big safety pins, two rubber bands cut from a bike tube and 1-meter of insulated copper wire used for motor rewinding. The coil is wound using the battery as a former. One end of the coil is completely scraped of the insulation exposing the shining copper below. The other end is scraped only on three sides – the little remaining insulation on this end acts as an on-off switch. This improvised switch is the heart of the motor. This switch acts as the “brush” or the “commutator” of a DC motor. See video.
TOYS FROM TRASH
For the past ten years a focused team of competent and compassionate people have attempted to make science accessible and fun for children – especially the poor. The team works at the Children’s Science Center based at IUCAA (Inter-University Center for Astronomy & Astrophysics) Pune, India. They call them Toys from Trash – but each toy has deep science woven in its design. These low-cost science experiments use plastic bottles, tetrapaks, newspapers, broomsticks, postcards and other readily available stuff. For instance there are over a 100 activities using old plastic bottles. The group has documented 600 creative activities in short videos which have been dubbed in 18 different languages by volunteers. In the last 4 years the video viewership has surpassed the 25-million mark. With a large, dynamic, young and educated workforce India is uniquely poised to promote science learning. Apart from helping students in far flung villages of India, it can also assist children in resource starved countries of Africa, Asia and Latin America. Please do visit our website and support us in this work.