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Alison Kiddle

Works at University of Cambridge

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### Alison Kiddle

Shared publicly -This is one of our latest problems. I'm particularly proud of the animated egg dropping, although I've had complaints that it doesn't seem to be behaving as an object falling under gravity should.

Enjoy!

https://nrich.maths.org/10870

Enjoy!

https://nrich.maths.org/10870

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### Alison Kiddle

Shared publicly -Quite a lot of nice maths can be explored from this starting point. Would love to know what questions it prompts for other people!

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### Alison Kiddle

Shared publicly -So here's the latest problem I've been playing with. You have a set of numbered cards and a set of blank cards. Here's a process - choose any two of your numbered cards, write their (positive) difference on one of your blank cards, and replace the two original cards with your new card. (So if you started with n cards, you now have n-1 cards.)

Keep doing this until you only have one card left.

The original problem that was posed to me was as follows: if you start with cards numbered 1-100, prove that when you have one card left it has an even number on it.

Once I'd proved that, I played around a bit. Here's some questions I enjoyed exploring: What sets of cards could I start with that guarantee finishing with an even number? What even finishing numbers are possible with the 1-100 set in the original problem? Given a set of cards with the numbers 1-n, what could the last card have on it?

Would love to hear any other interesting questions that occur. And of course, always interested to hear other people's solutions too!

Keep doing this until you only have one card left.

The original problem that was posed to me was as follows: if you start with cards numbered 1-100, prove that when you have one card left it has an even number on it.

Once I'd proved that, I played around a bit. Here's some questions I enjoyed exploring: What sets of cards could I start with that guarantee finishing with an even number? What even finishing numbers are possible with the 1-100 set in the original problem? Given a set of cards with the numbers 1-n, what could the last card have on it?

Would love to hear any other interesting questions that occur. And of course, always interested to hear other people's solutions too!

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I don't usually bother, but I suppose you're used to putting hashtags on things 'cos you post everything on that other site rather than here :P

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### Alison Kiddle

Shared publicly -Bag based on tutorial at http://www.craftster.org/forum/index.php?topic=51187.0#axzz2Wt7rTtyj. Hoping to make another one soon but this time get the patches a bit neater. A rotary cutter and mat would be useful I think, as the fabric was quite hard to cut in a straight line. The method for making a lined reversible bag was very straightforward once the patchwork pieces were joined though, and I reckon I could have a go at some other geometric designs for the patchwork. As long as the finished piece of fabric is a rectangle, I can adjust the dimensions of the lining and finish off as per the instructions.

Had great fun making this, and pleased with how it's turned out, as I think it may be my first piece of machine-sewing in 2013 :-o

Had great fun making this, and pleased with how it's turned out, as I think it may be my first piece of machine-sewing in 2013 :-o

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### Alison Kiddle

Shared publicly -Here's my latest project on NRICH. Lots more modules to be released over the course of the year, so if you have any suggestions for useful STEP preparation stuff then drop me a line.

https://nrich.maths.org/STEP

https://nrich.maths.org/STEP

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I'm hoping to redo all the drag'n'drops when I get the chance, so this is just a stop-gap until I have time. Unfortunately our tech guru has done loads of new stuff with our app development environment over the summer so I'll have to learn a bunch of new stuff first. But it will be worth it if I can make drag'n'drops easily - they're such a great learning tool.

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### Alison Kiddle

Shared publicly -I'm looking at all the different ways that people solve this problem:

On my last birthday, my friend said to me:

"In 15 years' time, your age will be the square of your age 15 years ago!"

Can you work out how old I am?

Was there ever a time in my life when I had other birthdays that were special in this way?

For example, could I have said:

"In 3 years' time, my age will be the square of my age 3 years ago"

or:

"In 4 years' time, my age will be the square of my age 4 years ago"

or:

"In 5 years' time, my age will be the square of my age 5 years ago"

or:

"In 6 years' time, my age will be the square of my age 6 years ago"

or...?

If you fancy having a go and then letting me know how you did it, I'd be grateful!

On my last birthday, my friend said to me:

"In 15 years' time, your age will be the square of your age 15 years ago!"

Can you work out how old I am?

Was there ever a time in my life when I had other birthdays that were special in this way?

For example, could I have said:

"In 3 years' time, my age will be the square of my age 3 years ago"

or:

"In 4 years' time, my age will be the square of my age 4 years ago"

or:

"In 5 years' time, my age will be the square of my age 5 years ago"

or:

"In 6 years' time, my age will be the square of my age 6 years ago"

or...?

If you fancy having a go and then letting me know how you did it, I'd be grateful!

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9 comments

Yes it makes sense, I've seen someone else work it out in a similar way.

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### Alison Kiddle

Shared publicly -I made a 'gingerbread' cottage, out of felt instead of gingerbread. It has lights and is shiny. If you want to make one, I made instructions: https://docs.google.com/document/d/1yJVD2Sb4V6y4KFBkD8CIrlTeGcnU-z0Eu9d3vHUwqW0/edit?usp=sharing

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### Alison Kiddle

Shared publicly -Like animated gifs? Then you're going to LOVE our latest collection of resources... https://nrich.maths.org/10791

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### Alison Kiddle

Shared publicly -I'm tired at work today, because of +Ian Glover who sent me this the other day. Pleased to say I solved it at last, slightly disappointed that my crazy brain decided 1:30am was the best time to work on it!

Also it's got me thinking about the bloody blue-eyed islanders again...

http://www.thebigquestions.com/2013/10/08/tuesday-puzzle-3/

Also it's got me thinking about the bloody blue-eyed islanders again...

http://www.thebigquestions.com/2013/10/08/tuesday-puzzle-3/

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### Alison Kiddle

Shared publicly -Warning: contains me.

New video now online to show you how to play power countdown http://nrich.maths.org/6448

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2 comments

Hey, that hadn't occurred to me! Neat!

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In her circles

54 people

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- University of Cambridgepresent

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Introduction

Former maths teacher now working for http://nrich.maths.org, when I'm not doing maths/education related stuff I'm probably knitting, sewing or crocheting.

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Female