3 Easy science experiments to try at home
September 9, 2022
Having fun with STEM doesn’t need to be complicated.
Science, or the “catch-all” term we now use, STEM, is all about discovering how our world works, which means that science – and the chance to experiment with it – is all around us. So, helping your child delve into the world of STEM doesn’t mean you have to invest in any specific toys or kits. You can find what you need for fun and educational experiments lying around at home. Read on and try some for yourself.
Safety note: remember safety first! Always. Always wear gloves, aprons and goggles if any hazardous materials are being used, and always chat to your children about the possible dangers of trying things without an adult present.
1. Make water walk
What you need:
- 5 to 10 small, glasses or plastic cups
- Food colouring in various colours
- 5 to 10 paper towels
- Water
How to do it:
- Place your cups in a row with a 2cm space between each and fill each cup ¾ up with water
- Place 5 drops of food colouring in each cup of water – each cup gets a different colour
- Fold each paper towel in half lengthwise, and then fold each in lengthwise again – you want a narrow piece of paper towel that will fit into the cups. Trim the lengths of the paper towel if needed
- Now place one half of a folded piece of paper towel in the first cup, and the second half in the second cup
- Repeat this with each cup, so that you have a trail of paper towel from one cup to the next
- Watch as the coloured water crawls up each paper towel, and continues to move into the next cup, colouring the water in it too.
The science explained:
The water moves up through the fibres and gaps in the paper towel in a process that’s called ‘Capillary Action’. This is essentially how water and nutrients travel from a plants roots through to its stems and leaves – the water travels up the capillary tubes (which are the gaps in the paper towels fibres) against gravity, because of the forces between the water and the fibres that are interacting with each other.
2. What’s on my teeth?
What you need:
- 4 Eggs
- 4 Glasses or plastic cups
- Carbonated cooldrink, preferably dark in colour
- Vinegar
- Toothpaste
- Marker and sticky notes
How to do it:
- Fill two glasses halfway with the fizzy cooldrink, and label one as Cooldrink 1 and the other as Cooldrink 2 using the sticky notes
- Fill the other two glasses halfway with the vinegar or lemon juice and label them Vinegar 1 and Vinegar 2 accordingly
- Rub toothpaste over two of the eggs – you want to be sure that they are covered all over with quite a thick layer
- Place one toothpaste-covered egg in the cup labelled Cooldrink 1 and place the other toothpaste-covered egg in the cup labelled Vinegar 1
- Next place the remaining two eggs, that are not covered with toothpaste, in the cup labelled Cooldrink 2 and Vinegar 2 respectively
- Leave the eggs in the cups in a safe place for anything from 12 hours to 1 week
- Remove the eggs from each cup, rinse them and pat them dry with a towel or kitchen towel (make sure you keep track of what cup each eggs came from so that you can compare the results)
- Ask your child if they notice any differences in the colours of the eggs, then get them to feel them and tell you if there are any differences.
- The egg that was covered in toothpaste and placed in the Cooldrink 1 cup should look much like it did at the beginning, while the egg with no toothpaste, placed in the Cooldrink 2 cup will be discoloured
- Similarly, the egg that was covered in toothpaste and placed in the Vinegar 1 cup will feel much like it did at the beginning, but the egg with no toothpaste placed in the Vinegar 2 cup will be soft to the touch.
The science explained:
By placing the eggs in different liquids, you are exploring the reactions of acids and bases when they come into contact with one another. Plus, this experiment is a great way to convince your child to brush their teeth! The eggshells represent the enamel on your child’s teeth. When they came into contact with the cooldrink, they were stained – much like our teeth can get stained by food and drink. The vinegar broke the eggshell down, which shows how our teeth can form cavities if not cared for. But, the eggs covered in toothpaste didn’t get stained or worn down, showing that brushing our teeth helps protect them and keep them strong.
3. What is amplification?
What you need:
- An empty toilet roll inner
- 2 paper cups
- Scissors and a craft knife
- Pencil
How to do it:
- Trace the shape of the bottom of your phone on the toilet roll
- Cut this out using the craft knife – this slot will form the base that holds your phone in this DIY amplifier
- Now trace the end of the toilet roll on the side of a paper cup and repeat for the second paper cup
- Cut these shapes out of the paper cups – these are going to be the ‘speakers’
- Attach a paper cup to each end of the toilet roll
- You can decorate your amplifier with washi tape, paint it, or even cover it in glitter
- Put your favourite song on and place the phone into the slot you’ve made for it, then listen to how it changes the sound.
The science explained:
This one is all about sound waves, showing you how sound travels through air, water or another medium to reach our ears, and how directing those waves in certain ways affects how we hear them. When you listen to music on your phone without the amplifier, the sound waves travel all around you in the air – they are spread out around the room. When you put the phone into the DIY amplifier, the sound waves are directed through the toilet roll tube and out of the paper cup speakers. Because the sound has been directed and focused, you hear it louder (and it’s not as tinny).
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The journey to building global leaders begins long before Matric year. For the Crawford International Class of 2025, it reflects three years of focused preparation, academic support and personal growth through the Crawford Matric Preparation Programme. In the 2025 Independent Examination Board National Senior Certificate examinations, Crawford International students achieved a total of 1 428 distinctions across the group. Twenty-one students recorded overall averages of 90% and above, placing them among the country’s top performers, while a further 126 students achieved averages between 80 and 89%. Among the group’s top academic performers are: Manzil Harikaran Giandev from La Lucia with 11 distinctions, including a 100% in Engineering Graphics Design Sashen Ramlal from Lonehill with 10 distinctions. Shweta Singh from Lonehill earned 9 distinctions. Dristhi Ramsumer from North Coast and Celia Wentzel from Sandton earned 9 distinctions. Sanjana Rajkaran from La Lucia earned 8 distinctions. Tayur Lushen Moodley from North Coast: 8 distinctions. Talia Govender and Keith Makadzange from Pretoria: 8 distinctions. Justin Sher and Mthokozisi Buthelezi from Sandton: 8 distinctions. Together, these students represent the highest individual academic achievements across the group. Beyond individual results, Crawford International students also earned national recognition through the IEB. Seven Commendable Achievement Awards were awarded to students ranked in the Top 5% nationally across five or more subjects. Eight Outstanding Achievement Awards were secured by students ranked in the Top 5% nationally across six or more subjects. Dr Siza Majola, Managing Director of Crawford International, shared: “Congratulations to the Matric Class of 2025. This milestone marks the culmination of years of commitment, perseverance and personal growth. You have faced challenges with resilience, embraced learning and demonstrated the determination required to succeed. As you step into the next chapter, remember that your Crawford education has equipped you with the confidence, leadership skills and values to navigate a world full of opportunity. Your achievements are also a reflection of the unwavering support of parents and teachers who walked this demanding journey with you. Their guidance and belief have played a vital role in your success. Well done, Matric Class of 2025. We are proud of all you have achieved and excited to see what lies ahead.” While these outcomes are academic in nature, Crawford International places equal value on leadership development, sport, service and collaboration. Students are encouraged to lead on the sports field, in cultural spaces, through student leadership structures and within their communities. This approach ensures that students leave school not only well prepared for tertiary study but equipped to contribute meaningfully to diverse environments. Distinctions by Campus: Crawford International Sandton College 370 distinctions Average of 3.6 distinctions per candidate Crawford International La Lucia College 316 distinctions Average of 3.19 distinctions per candidate Crawford International Pretoria College 219 distinctions Average of 2.55 distinctions per candidate Crawford International North Coast College 130 distinctions Average of 2.50 distinctions per candidate Crawford International Lonehill College 253 distinctions Average of 2.16 distinctions per candidate Crawford International Ruimsig College 140 distinctions Average of 1.75 distinctions per candidate Crawford International congratulates every student, teacher and family who contributed to this collective success. We wish the Class of 2025 the very best for the future.
ALUMNI SPOTLIGHT: ROXANNE VAN DER WESTHUIZEN Crawford International Lonehill | Class of 2009 From the banking halls of one of South Africa’s most prestigious financial institutions to the stages and studios of New York City, Roxanne Van der Westhuizen’s story is one of courage, reinvention and the pursuit of purpose. Chasing the Calling After matriculating from Crawford International Lonehill in 2009, Roxanne was accepted into the Psychology programme at the University of Cape Town. A sudden family crisis and financial hardship brought her back to Johannesburg, where she began working to support her family. Years later, determined to finish what she started, she enrolled at Varsity College in Sandton. Balancing motherhood, full-time employment and a rigorous academic load, she earned her degree with distinction, graduating at the top of her class. Her career began at Investec Bank, where she rose through the ranks, first in client services and later in data analytics. Her success came through persistence, grit and repeated setbacks that ultimately redirected her. A moment of deep personal reflection led her to reconnect with a long-suppressed calling, storytelling through performance. In a bold leap of faith, she left her corporate life behind and relocated to New York to pursue acting. There, she studied under renowned acting coach Terry Knickerbocker, known for mentoring names such as Sam Rockwell and Daniel Craig. She was named Student of the Season at his studio. Today, Roxanne stars in stage and screen productions across the U.S., including her lead role in the upcoming film Emancipation of the Past (July 2025), and a standout performance as Regina in Not to Be Played With (available on Tubi and AppleTV). She is also developing her own series, which she plans to take to festivals and production houses. Achievements and Projects Lead role in Emancipation of the Past (2025 release) Featured in Not to Be Played With on Tubi and Apple TV Collaboration on Spicy Bob alongside Pete Simpson of Blue Man Group Student of the Season at Terry Knickerbocker Studio Creator and writer of a new series currently in development Roxanne reflects on her journey and earning one of her biggest roles yet, “this is the most difficult thing I’ve ever had to do, but also the most enriching. The vulnerability required in acting is daunting, but it connects me to myself and others in ways I never imagined. Despite the false starts and failures, I am exactly where I am meant to be.”
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