7992
/www/nrich/html/content/id/7992/
1
2012-02-01T00:00:00
<?xml version="1.0" encoding="UTF-8"?>
<mdoxml version="1.0"><br></br>
<p>Here is the alphabet:</p>
<p style="font-family: Comic Sans MS; text-align: center;">a b c d e f g h i j k l m n o p q r s t u v w x y z</p>
<p> </p>
<p>I have made a code that means we move $3$ places to the left to discover what the code stands for. But what will happen to</p>
<p style="font-family: Comic Sans MS; text-align: center;">a b c ?</p>
<p>They pick up the letters left over at the end of the alphabet so that they become</p>
<div style="text-align: center;">
<p style="font-family: Comic Sans MS;">x y z </p>
</div>
<div>You can think of the letters as if they were arranged on a wheel like this:</div>
<div style="text-align: center;"><mdo:image alt="A coding wheel" src="codingWheel.png" style="width: 356px; height: 355px;"></mdo:image></div>
<div style="text-align: center;"><a class="pdflink" href="/content/id/7992/CodingWheelCutout.pdf"><span class="pdflink">Print out and make</span></a></div>
<div> </div>
<div>So can you work out what these codes stand for?</div>
<div> </div>
<div>
<p style="font-family: Comic Sans MS; text-align: center;">sdw - d - fdnh,</p>
<p style="font-family: Comic Sans MS; text-align: center;">wkh - zhvw - zlqg - eorzv,</p>
<p style="font-family: Comic Sans MS; text-align: center;">brx - duh - zrunlqj - kdug</p>
</div>
<div> </div>
<p>Can you invent some messages of your own?</p>
<p>Can you create some different ways of coding?<br></br>
</p></mdoxml>
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<mdoxml version="1.0"><p><span class="editorial">Alex from Mortimer St. Mary's School in England sent in a challenge for us at Nrich which turned out to be the word, antidisestablishmentarianism, once thought to be the longest English word. Can you see what the code was for this very long word?</span></p>
<p><span class="editorial">The solutions of "pat a cake, the west wind blows, you are working hard" were sent in by many of you. Here are the ones that we received; Martin and Jonah from Goodleigh School; Christy, Charlie and Callum from St. Cecilia's Wandsworth; SJF Y6 Maths from G&T School; Zetta from Thomas's Battersea; Dan from Whitby Community School; Tallulah, Anna and Aishwarya from
Salcombe Prep School; Kavi from St. James the Great; Kavya from Hymers College; Suchita from Elsley School; Tom and Henry from Redgate School and Toony $5/4S$ Toongabbie Public School Australia.</span></p>
<p><span class="editorial">Sana and Freya from The British Manila in the Philippines wrote the following:</span></p>
<p>sdw - d - fdnh = pat a cake</p>
<p>wkh - zhvw - zlqg - eorzv = the west wind blows</p>
<p>brx - duh - zrunlqj - kdug = you are working hard<br></br>
nrich is awesome = qulfk - lv - dzhvrph</p>
<p>world peace = zruog - shdfh</p>
<p>math is fun = pdwk - lv - ixq</p>
<p>Think of a word in the dictionary then take the one before it and spell<br></br>
that word backwards e.g.</p>
<p>a = starter word</p>
<p>zoom-lens = word before a in dictionary</p>
<p>a = snel-mooz<br></br>
(for word before starter word spelt backwards).</p>
<p><span class="editorial">Year 5 from St. John's wrote:</span></p>
<p><br></br>
1.PAT-A-CAKE<br></br>
2.THE-WEST-WIND-BLOWS<br></br>
3.YOU-ARE-WORKING-HARD</p>
<p>WE FOUND OUT NRICH'S QUESTIONS BY PRINTING THE CODE WHEEL OUT. WE USED IT TO FIGURE OUT THE ANSWERS. WE FOUND OUT ABOUT MORSE CODE AND MADE OUR OWN CODE.</p>
<p>.-- . .- .-. . ..- ... .. -. --. -- --- .-. ... . -.-. --- -.. . ---<br></br>
-.<br></br>
-. .-. .. -.-. .... </p>
<p>THAT EQUALS:<br></br>
WE ARE USING MORSE CODE ON NRICH</p>
<p> </p>
<p><span class="editorial">Thank you for all of these. It shows you really worked hard but enjoyed it along the way. How about sending in to next month's challenges?</span></p>
<p> </p>
<p> </p></mdoxml>
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<mdoxml version="1.0"><div class="embed">
<h2>Some Secret Codes</h2>
<br></br>
<p>Here is the alphabet:</p>
<p style="text-align: center; font-family: Comic Sans MS;">a b c d e f g h i j k l m n o p q r s t u v w x y z</p>
<p> </p>
<p>I have made a code that means we move $3$ places to the left to discover what the code stands for. But what will happen to</p>
<p style="text-align: center; font-family: Comic Sans MS;">a b c ?</p>
<p>They pick up the letters left over at the end of the alphabet so that they become</p>
<div style="text-align: center;">
<p style="font-family: Comic Sans MS;">x y z </p>
</div>
<div>You can think of the letters as if they were arranged on a wheel like this:</div>
<div style="text-align: center;"><mdo:image alt="A coding wheel" src="codingWheel.png" style="width: 356px; height: 355px;"></mdo:image></div>
<div style="text-align: center;"><a class="pdflink" href="/content/id/7992/CodingWheelCutout.pdf"><span class="pdflink">Print out and make</span></a></div>
<div> </div>
<div>So can you work out what these codes stand for?</div>
<div> </div>
<div>
<p style="text-align: center; font-family: Comic Sans MS;">sdw - d - fdnh,</p>
<p style="text-align: center; font-family: Comic Sans MS;">wkh - zhvw - zlqg - eorzv,</p>
<p style="text-align: center; font-family: Comic Sans MS;">brx - duh - zrunlqj - kdug</p>
</div>
<div> </div>
<p>Can you invent some messages of your own?</p>
<p>Can you create some different ways of coding?</p>
<p> </p>
<p> </p>
<p><br></br>
<br></br>
</p>
</div>
<br></br>
<h3><span style="font-weight: bold;">Why do this problem?</span></h3>
<div>This <a href="http://www.nrich.maths.org/7992">activity</a> enables pupils to use some simple counting in addition and subtraction situations. It also starts pupils thinking about codes and the fun that can be had with them. Here is a <a href="http://nrich.maths.org/8116">link</a> to a short article from Jenny Murray about how she developed her interest in coding.</div>
<br></br>
<h3>Possible approach</h3>
<div>The activity can be started off as a game in which the teacher says something about some secret ideas/thoughts they are having when looking at the alphabet. So, with the alphabet displayed as separate cards in order in front of the pupils they say they want to spell out (eg dog) but the teacher carefully goes for g r j instead of d o g.This will obviously lead to some discussiion. Perhaps
other examples will be needed until the "rule" is extablished.</div>
<br></br>
<h3>Key questions</h3>
<div>What do you think has happened?</div>
<div>What letters will you choose?</div>
<div>I see you've made your own code, can you tell me about it?</div>
<br></br>
<h3>Possible extension</h3>
<div>Have a look at this <a href="/content/id/7992/Secret%20C%202.pdf">Secret Codes 2.pdf</a> as an extension</div>
<br></br>
<h3>Possible support</h3>
<div>Some children will need the alphabet individually in front of them.</div>
<p><br></br>
<br></br>
<br></br>
</p>
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<p>You could try writing the letters round in a circle so that it is easier to count forwards and backwards. Use the <a href="/content/id/7992/codingWheel.png">wheel</a> we have created to help you.</p>
<br></br></mdoxml>
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Some Secret Codes
Can you follow the rule to decode the messages?
Calculations and Numerical Methods
Addition & subtraction
Numbers and the Number System
Counting
Applications
Codes and cryptography
Admin
Upper primary mapping document