Magic letters

Charlie has made a Magic V. Can you use his example to make some more? And how about Magic Ls, Ns and Ws?

Problem

 Magic Letters printable worksheet

The problem is explained below, but you may wish to go to the Getting Started page to watch a video of the NRICH team presenting the initial challenge.

Charlie has made a Magic V with five consecutive numbers:

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The numbers from 1 to 5 arranged in a V-shape, in the order 3, 4, 1, 2, 5.

It is a Magic V because each 'arm' has the same total.

 

Alison drew this magic V:       

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The numbers from 1 to 5 arranged in a V-shape, in the order 4, 3, 1, 5, 2..

Charlie said "That's really just the same Magic V as mine!"

What do you think Charlie meant?

There are six more Magic Vs that are the same as Charlie's - can you find them all?

Click below to check you have.

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The numbers from 1 to 5 arranged in a V-shape, in the order 3, 4, 1, 5, 2.
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The numbers from 1 to 5 arranged in a V-shape, in the order 4, 3, 1, 2, 5.
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The numbers from 1 to 5 arranged in a V-shape, in the order 5, 2, 1, 3, 4.
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The numbers from 1 to 5 arranged in a V-shape, in the order 5, 2, 1, 4, 3.
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The numbers from 1 to 5 arranged in a V-shape, in the order 2, 5, 1, 4, 3.
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The numbers from 1 to 5 arranged in a V-shape, in the order 2, 5, 1, 3, 4.

 

Can you find all the possible Magic Vs that use the numbers $1$ to $5$ and are different from Charlie's?

How can you be sure you have found them all?

 

What happens if you use the numbers from $2$ to $6$? Or from $3$ to $7$? Or $4$ to $8\dots$?

Here is a  spreadsheet to help you investigate Magic Vs made from five consecutive numbers.

 

Can you describe an efficient strategy to find all Magic Vs for any given set of numbers?

Can you use your strategy to find all the possible Magic Vs that use the numbers $987, 988, 989, 990, 991$?

 

Can you find a Magic V where each arm has a total of 60? Or 1000? Or...?

Can you find more than one?

Can you find a Magic V for any arm total? 

 

Charlie and Alison drew some more letters, to see if they could make them magic - that is, using consecutive numbers to make equal arm totals.

Magic L?Magic N?Magic W?
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7 circles arranged in the shape of the letter L. There are 4 circles on the vertical part of the L, and 3 horizontally.
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7 circles arranged in the shape of the letter N. There are three diagonally upwards, three downwards, then 3 upwards.
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7 circles arranged in the shape of the letter W. There are 3 downwards, 3 upwards, 3 downwards, then 3 upwards.

Investigate some of these Magic Letters in the same way that you explored Magic Vs.

What general conclusions can you reach?

 

You can use this spreadsheet to explore.

 

Click here for a poster version of Magic Vs.