by David Shaw, 29 June 2022 | 0 comments

Difficulty: Fun A fast passenger train leaves Sydney Central station, headed for Broken Hill. At the same time, a slow freight train, moving at only half the speed of the passenger train, leaves Broken Hill station, headed for Sydney Central. When they meet, which train is closer to Sydney?

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by David Shaw, 23 June 2022 | 0 comments

It sounds like a perfect way to make money – scientists from The Australian National University (ANU) are now selling random numbers over the internet! But before you start your own business writing whatever number pops into your head, there’s something special about these numbers.

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by David Shaw, 16 June 2022 | 2 comments

How many 1s does it take to write out the number eleven thousand, eleven hundred and eleven?

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by David Shaw, 2 June 2022 | 2 comments

A farmer goes to the local mill to get some wheat ground into flour. The miller doesn’t ask for money – instead, they take one tenth of the wheat as payment. If the farmer wants 100 kilograms (kg) of flour at the end, how much wheat should they bring?

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by David Shaw, 24 May 2022 | 1 comments

The soma cube is a tricky puzzle! First, you’ll glue some cubes together into strange shapes. Then see if you can get those shapes to come together!

Continue reading Soma cubeby David Shaw, 18 May 2022 | 0 comments

Difficulty: Extreme! Srinivasa lives in a house on a short street, with houses on one side. The houses are numbered 1, 2, 3 and so on. He was practicing his addition when he noticed something strange.

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by David Shaw, 5 May 2022 | 0 comments

Difficulty: Tricky Mabel wanted to play noughts (O) and crosses (X), but she didn’t have anyone to play with. So she just took one go after another. Somehow, Mabel put Xs in 6 of the 9 squares without making a line of 3 Xs. Can you draw the board and work out which squares have…

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by David Shaw, 13 April 2022 | 0 comments

Difficulty: Tricky Willow has a staircase with 7 steps. She likes to walk down the staircase in different ways. Sometimes she takes 1 step at a time, and other times she skips a step and goes 2 at a time. If Willow mixes up these 2 types of steps, how many different ways can she…

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by David Shaw, 24 March 2022 | 0 comments

Difficulty: Extreme! These 2 brothers sold oranges for a living. On Monday: Josh priced his oranges at 2 for $3. He sold 30 oranges for $45. Zach priced his oranges at 3 for $4. He sold 30 oranges for $40. On Tuesday, they combined their prices, and sold their oranges in groups of (2 +…

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by David Shaw, 17 March 2022 | 0 comments

Rulers are great at measuring straight lines, but how do you measure a curvy line? Here’s one way, using a wonderfully messy diagram!

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