Dear all,

May's edition of NRICH is now live at http://nrich.maths.org where the 
mathematical theme this month is Scale. What comes to mind when you 
think of this topic? Perhaps your first thoughts are about 'things' 
getting larger or smaller. What things? Shapes? Numbers? Both?

Certainly the problems on NRICH this month focus on scale in terms of 
both these aspects. At Stage 1, Scaling Clowns 
<http://nrich.maths.org/public/viewer.php?obj_id=5591&part=index> asks 
you to compare the faces of clowns in pairs. What is the same and what 
is different in each case? Shape Mapping 
<http://nrich.maths.org/public/viewer.php?obj_id=5568&part=index> takes 
this idea a little further, exploring the changes that have happened to 
a shape and then choosing a shape that shows the same change but with a 
different start.

On a numerical theme, Multiplying with Lines 
<http://nrich.maths.org/public/viewer.php?obj_id=5612&part=index> 
invites you to watch a video clip of a method of multiplication. Can you 
explain why it works? Would it always work?

When we measure something we often use a scale which considers the size 
of one thing in terms of another. This is exactly what you will 
investigate in A Scale for the Solar System 
<http://nrich.maths.org/public/viewer.php?obj_id=5634&part=index> . What 
could astronomers observe, and what calculation would they need to do, 
to know the ratio between the Venus to Sun distance and the Earth to Sun 
distance?

At Stage 5, the problem What do Functions do for Tiny X 
<http://nrich.maths.org/public/viewer.php?obj_id=5621&part=index> ? asks 
you to explore four curves graphically for smaller and smaller values of 
x. As you zoom in the scale what do you notice happening to the graphs 
in each case? What similarities do the functions have as we zoom in? 
What differences do they exhibit?

And if that's not enough to keep you busy, there are plenty of other 
resources which feature scale on the Millennium Mathematics Project's 
<http://mmp.maths.org> websites. These Plus <http://plus.maths.org> 
articles explore the problems and strategies involved in finding a good 
scale for processes which interest us: Near miss or normal? 
<http://plus.maths.org/latestnews/sep-dec03/torino/index.html> and 
Population ex-explosion?. 
<http://plus.maths.org/issue17/news/popn/index.html> You may also like 
to look at the Motivate Project's <http://motivate.maths.org> session 
investigating the Transit of Venus 
<http://motivate.maths.org/conferences/conference.php?conf_id=46> to see 
how the distance from the Earth to the Sun is used as a scale for the 
Solar System.

We hope you enjoy this month's offerings and look forward to receiving 
your solutions.

With best wishes from The NRICH Team


-- 
Liz Pumfrey
NRICH Primary Coordinator
University of Cambridge Centre for Mathematical Sciences
Wilberforce Road
Cambridge
CB3 0WA
01223 764246
www.nrich.maths.org

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