# Blog

## How old is my mum?

By David Shaw, 25 July 2018

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

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## Numbers and letterboxes

By David Shaw, 11 July 2018

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.

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## Fractional puppies

By David Shaw, 27 June 2018

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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## Which bus?

By David Shaw, 13 June 2018

I caught a bus the other day with a very interesting number. Can you work out the number on the bus?

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## Lots of eights brainteaser

By David Shaw, 30 May 2018

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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## Half of 12 brainteaser

By David Shaw, 16 May 2018

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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## Square and cube number brainteaser

By David Shaw, 2 May 2018

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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## Jenny’s building site brainteaser

By David Shaw, 18 April 2018

Jenny’s hard at work on a building site. This problem will tax her brain as well as her brawn!

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## Terri’s transport brainteaser

By David Shaw, 4 April 2018

Terri’s just about to leave to go to a party. She’s trying to work out whether to walk or ride her bike. If she walks at a brisk pace of 5 kilometres per hour, she’ll be an hour late. If she rides her bike at 10 kilometres per hour, she’ll be an hour early!

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