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VAT increased to 20% – is it worth panic buying?

The coalition government has announced that VAT will increase from 17.5% to 20% on January 4th 2011.

Problem

A TV is advertised at £1000 including VAT at 17.5%.

VAT is increased to 20%.  What will the new price tag be?

Solution

The immediately apparent answer is £1025, because we’ve “added 2.5%”.  But that’s not quite right…

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June 24, 2010   No Comments

The Traversal Problem (3 dimensions)

[This problem is related to the (easier) 2-dimensional Diagonal Problem - click here for a full solution]

1. Imagine a cuboid made up of lots of little cubes.

2. Imagine a straight line (or “traversal”) connecting two opposite vertices of the cuboid

3. How many little cubes does the line pass through?

cuboid_colour2 Diagram 1

Note: Cubes are only counted if the traversal passes through them, so if your traversal goes exactly through a vertex or an edge separating cubes within the cuboid, then it is not considered to pass through the adjacent cubes.  In the 2×3×4 example shown, the traversal actually passes through an edge in the centre of the cuboid.

Problem: How many cubes does a traversal pass through in a 90×120×140 cuboid?

(Hint: Start small!)

June 24, 2010   3 Comments

A Brief History of Mathematics with Professor Marcus Du Sautoy

Professor of Mathematics Marcus du Sautoy reveals the personalities behind the calculations and how mathematics is the driving force behind modern science and exploration.

Ten fascinating 15-minute radio programmes, all this week and next week on BBC Radio 4 at 3.45pm.

Catch up on BBC iPlayer (UK internet users only)

Go to A Brief History of Mathematics site

June 16, 2010   No Comments

The Diagonal Problem (2 dimensions)

  1. Draw a rectangle on squared paper.
  2. Draw a diagonal across your rectangle.
  3. How many squares does it pass through?

Diagram 1

Note: If your diagonal goes exactly through a point, like in the 2×4 example, then it is not considered to pass through either of the diagonally adjacent squares.

Problem: How many squares does a diagonal pass through in a 190×884 rectangle?b

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June 14, 2010   1 Comment

The Shrinking Square

Fullscreen capture 19022010 221332.bmp

Problem:
When the area of the green square is two-fifths of the area of the whole diagram, what fraction do the four black triangles occupy?

Open the post to play with a Java applet.

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February 19, 2010   1 Comment

Christmas in Numbers

Happy Christmas from The Secret Garden of Maths!
http://news.bbc.co.uk/1/hi/uk/8428406.stm

December 25, 2009   No Comments

No-Numbers Geometry

Can you work out the size of angle xº?

int-ext-angles problem

That’s a regular hexagon and a regular pentagon.  Good luck!

(Hint: Consider the size of the interior angles in a polygon, the sum of angles round a point, and the sum of angles on a line)

(This is my first post in quite a while – apologies for the delay. I’ve been trying to become a qualified teacher!). [Read more →]

November 30, 2009   3 Comments

A Neat Visual Method for Multiplication

October 18, 2009   1 Comment

Vacation Weight Loss! You could lose grams!

Want to lose weight fast?  Then jump on a plane to the equator!

Title image

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October 15, 2009   1 Comment

Day of the Devil

StephenGateley

I was very saddened to hear today of Stephen Gateley’s sudden death.  Stephen gave a huge amount to pop music and was an inspirational figure.  May he rest in peace.

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October 11, 2009   No Comments