Why do I have to wash my hands?

How many times a day do you wash your hands? I probably wash mine 100 times! That might seem like a lot but I wash them every time I go to the loo, after I feed or stroke the cat, before and during cooking, before I eat (and sometimes afterwards), after I stack dirty dishes in the dishwasher, and each time I clean up mess and spills around the house.

So why do I wash my hands so often? And why is hand-washing important?


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How long would it take a cheetah to run around the world?


Cheetahs are big cats that live in Africa, Asia, India and the Middle East. They can run super-fast to catch their prey when they are hunting for food. But running at top-speed is very tiring, so cheetahs only do it for short periods of time.

My 6-year-old wondered, what if a cheetah could run at its top-speed without getting tired…? How long would it take the cat to run all the way around the world?

Let’s do the maths and find out!

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How do mermaids go to the loo?

My 6-year-old loves dressing up as a mermaid and is disappointed that she can’t become a mermaid when she grows up. But the thing she really wants to know is, how do mermaids wee and poo?


The trouble is, mermaids are imaginary creatures so there aren’t any real ones that we can study. But if we believe that mermaids are like humans with a fishy tail instead of legs, perhaps we can make a prediction about how they might go to the loo?

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How does temperature work?


This question was asked on a cold Winter’s day. The water in the bird bath had frozen and I used hot water from the kettle to thaw it so the birds could drink. When I explained to my 6-year-old that water freezes at zero degrees Celsius, she wondered if that was the coldest that things can get. But it isn’t – in fact some things can get much, much, much colder!

So what happens when things get hot or cold and how do we measure temperature?

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