# What's new

## Unchecker the board Activity

by David, 22 October 2020 | 0 comments

Here’s a quick sliding puzzle to get your brain pumping. See if you can separate the light and dark counters in as few moves as possible!

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## Two eggs brainteaser Brainteaser

by David, 14 October 2020 | 3 comments

Difficulty: Taxing Jenny found a strange sum written on a piece of paper: EGG + EGG = PAGE Each letter represents a different digit, so P might be 1, for example. Can you work out what the sum really is?

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## Mathematical cloning brainteaser Brainteaser

by David, 30 September 2020 | 0 comments

Difficulty: Taxing Grab a calculator (or a pen and paper) Choose a three-digit number (e.g. 123) Multiply it by 7 Multiply the answer by 11 Multiply that answer by 13 You will get your starting number written out twice! (e.g. 123 123) The question is, can you work out why?

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## A magic triangle brainteaser Brainteaser

by David, 16 September 2020 | 1 comments

Difficulty: Tricky We’re going to make a magic triangle! Take the numbers 1–6 and arrange them in a triangle with three numbers on each side. Swap them around until the sides all add up to the same number.

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## A past puzzle Brainteaser

by David, 26 August 2020 | 1 comments

Difficulty: Taxing Here’s a beautiful artwork from 1895, titled Mental calculation. In public school of S. A. Rachinsky, painted by Nikolay Bogdanov-Belsky. Can you solve the puzzle the kids are pondering? If you can’t quite see the equation, here it is:

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## Geodesic rings Activity

by David, 20 August 2020 | 0 comments

Craft yourself a mathematical ring to learn about straight lines on donuts. Don’t laugh, they do exist!

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## Playing with shapes brainteaser Brainteaser

by David, 19 August 2020 | 0 comments

Difficulty: Tricky Gertrude has a collection of shapes that she likes to arrange in patterns. She starts with a regular hexagon with 10 cm sides, and three regular triangles that also have 10 cm sides. She arranges the triangles around the hexagon, and then lines them up. In the end, one side of each triangle…

Continue reading Playing with shapes brainteaser

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by David, 3 August 2020 | 4 comments

Difficulty: Fun I’m thinking of three numbers. They are consecutive counting numbers. When you add the first two numbers together, you get the third number. What numbers am I thinking of?

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## Two birthday brainteasers Brainteaser

by David, 22 July 2020 | 1 comments

Difficulty: Tricky Ari was 10 on her last birthday, and will be 12 on her next birthday. How can this be true? Lachlan was 8 on his last birthday, and will be 12 on his next birthday. How can this be true?