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  <resource>
  <id>7833</id>
  <path>/www/nrich/html/content/id/7833/</path>
  <resourceTypeID>1</resourceTypeID>
  <last_published>0000-00-00T00:00:00</last_published>
  <indexXML>&lt;mdoxml version=&quot;1.0&quot;&gt;&lt;p&gt;I&amp;#39;ve noticed that the cans that were stacked by Zizi in a triangle were $4$ high. Not only that but I counted and found that she used  $10$ cans.&lt;/p&gt;
&lt;p style=&quot;text-align: center;&quot;&gt;&lt;mdo:image src=&quot;ten%20cans.jpg&quot; style=&quot;text-align: -webkit-auto;&quot;&gt;&lt;/mdo:image&gt;               &lt;mdo:image src=&quot;March%202012%20cans.jpg&quot;&gt;&lt;/mdo:image&gt;&lt;/p&gt;
&lt;p&gt;Pete had made a triangle just $3$ high and I noticed that he used just $6$. &lt;/p&gt;
&lt;p&gt;&amp;quot;Both even numbers!&amp;quot;&lt;/p&gt;
&lt;p&gt;On another table Cas made a triangle $5$ high and used an odd number this time, $15$! and Sophie made an even bigger one of $21$ this was $6$ high.&lt;/p&gt;
&lt;p&gt;&amp;quot;These were odd numbers!&amp;quot;&lt;/p&gt;
&lt;p&gt; &lt;/p&gt;
&lt;p&gt;What can you can about these pairs of even and then a pair of odds - will it often happen?&lt;/p&gt;
&lt;p&gt;What do you think?&lt;/p&gt;
&lt;p&gt;Can you prove that your ideas are right to others?&lt;/p&gt;
&lt;p&gt; &lt;/p&gt;&lt;/mdoxml&gt;</indexXML>
  <solutionXML/>
  <noteXML>&lt;mdoxml version=&quot;1.0&quot;&gt;&lt;br&gt;&lt;/br&gt;
&lt;h3&gt;&lt;span style=&quot;font-weight: bold;&quot;&gt;Why do this problem?&lt;/span&gt;&lt;/h3&gt;
&lt;div&gt;This &lt;a href=&quot;http://nrich.maths.org/7833&quot;&gt;activity&lt;/a&gt; provides an opportunity for pupils to both explore a mathematical pattern that is easily generated and find ways of proving what they can from their observations and beliefs.&lt;/div&gt;
&lt;br&gt;&lt;/br&gt;
&lt;h3&gt;Possible approach&lt;/h3&gt;
&lt;div&gt;text&lt;/div&gt;
&lt;br&gt;&lt;/br&gt;
&lt;h3&gt;Key questions&lt;/h3&gt;
&lt;div&gt;text&lt;/div&gt;
&lt;br&gt;&lt;/br&gt;
&lt;h3&gt;Possible extension&lt;/h3&gt;
&lt;div&gt;text&lt;/div&gt;
&lt;br&gt;&lt;/br&gt;
&lt;h3&gt;Possible support&lt;/h3&gt;
&lt;div&gt;text&lt;/div&gt;
&lt;br&gt;&lt;/br&gt;
&lt;br&gt;&lt;/br&gt;&lt;/mdoxml&gt;</noteXML>
  <clueXML/>
  <canonXML/>
  <end_user_role>2</end_user_role>
  <difficulty>3</difficulty>
  <keystage1>1</keystage1>
  <keystage2>1</keystage2>
  <keystage3>0</keystage3>
  <keystage4>0</keystage4>
  <keystage4plus>0</keystage4plus>
  <title>I've noticed that . . . .</title>
  <description></description>
</resource>