Construct-o-straws

Make a cube out of straws and have a go at this practical challenge.

Matchsticks

Reasoning about the number of matches needed to build squares that share their sides.

Little Boxes

How many different cuboids can you make when you use four CDs or DVDs? How about using five, then six?

World of Tan 20 - Fractions

Age 7 to 11Challenge Level

This activity follows on from World of Tan 19 - A Circular Problem.

Little Ming and Little Fung have homework to do before they can go into the yard to help the workers.

Little Ming: Mah Ling, why were fractions invented? Why are they so complicated?

Little Fung: I'm sure it isn't just us who don't understand fractions.

Little Ming: All I can remember is that what you do to the top you must do to the bottom.

Mah Ling: Yes, if you multiply or divide the top number by another number you must do the same to the denominator.

Little Ming: Does it matter if you do it to the bottom number first?

Little Fung: Does that apply to adding and taking a number from the numerator or denominator?

Mah Ling: No, no, no! You two sound so confused and you're confusing me.

Little Ming: Perhaps we should start again at the beginning.

Little Fung: What are fractions?

Mah Ling: They are part of a whole.

Little Ming: A hole?

Mah Ling: If something is divided into equal parts, one or more of these parts are called fractions.

Little Fung: You mean like a half or two thirds or three twenty-fifths?

Mah Ling: Yes, that's one type of fraction...

Little Ming: Oh no, you mean there are more types?

Mah Ling: There are also improper fractions...

Little Ming: No, no! I've had enough for today.

Little Fung: Let's finish this tomorrow when we don't have school and our heads aren't buzzing!

In the meantime, complete the silhouettes of the two chairs that Little Ming and Little Fung were sitting on.

Extra activities:
• Write down all the things you know about fractions!
• Have a go at this activity involving fractions of bars of chocolate. Where would you choose to sit to get the most chocolate? Why?

The story continues in World of Tan 21 - Almost There Now.