by David, 5 September 2018 | 0 comments

Peter’s just finished building a new staircase up to the attic. It just fits along the four-metre-long wall of his lounge room, and it’s three metres tall. It has exactly 15 steps. Peter wants to have a carpet running along the staircase. How long does it need to be?

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by David, 21 August 2018 | 0 comments

Can you work out the next letter in this sequence? H, T, Q, F, S, S, E, N, … Hint: There are numbers lurking behind those letters. And as it grows, this sequence is shrinking!

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by David, 8 August 2018 | 4 comments

Imagine your calculator is broken. Although it will still display numbers, only the 4 key, + key, = key and clear key work. Starting at 0, can you get the calculator to display 1000? What’s the fastest way, with the fewest button presses?

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by David, 25 July 2018 | 0 comments

Twenty years ago, my mum was twice my age. I’m 42 years old. How old is my mum?

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by David, 11 July 2018 | 0 comments

Tomas is putting a number on a letterbox. He puts on one digit. Then he adds another digit. Tomas looks at it and notices that it makes a number exactly five times the first digit. Tomas adds a third and final digit. Once again, Tomas looks at the number and notices that the three digit…

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by David, 27 June 2018 | 0 comments

Kelly has a pet store. She recently got in a whole litter of puppies and tried to sell them all. On the first day, she sold half of the puppies, plus half a puppy.

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by David, 13 June 2018 | 4 comments

I caught a bus the other day with a very interesting number.

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by David, 30 May 2018 | 0 comments

I want to find a number that is divisible by three. I also want all of its digits to be 8s. Does my number exist?

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by David, 16 May 2018 | 0 comments

You probably know that half of 12 is six. But the other day, I caught a glimpse of a clock peeking between buildings. At that moment, I noticed that sometimes, half of 12 is seven. How is this possible?

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by David, 2 May 2018 | 1 comments

When you multiply a whole number by itself, you get a square number. When you take three copies of a whole number and multiply them all together, you get a cube number. There’s only one two digit number that is both a square and a cube. Can you work out what number it is?

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