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<p><a href="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_cc593ur_04.gif"><img data-attachment-id="2595" data-permalink="https://justpuzzles.wordpress.com/2013/05/31/81/carte_francaise_coeur_04/" data-orig-file="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_cc593ur_04.gif" data-orig-size="81,116" data-comments-opened="1" data-image-meta="{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}" data-image-title="Carte_française_cœur_04" data-image-description="" data-image-caption="" data-medium-file="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_cc593ur_04.gif?w=81" data-large-file="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_cc593ur_04.gif?w=81" class="alignleft size-thumbnail wp-image-2595" alt="Carte_française_cœur_04" src="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_cc593ur_04.gif?w=105&#038;h=150"   /></a></p>
<p><a href="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_carreau_04.gif"><img data-attachment-id="2596" data-permalink="https://justpuzzles.wordpress.com/2013/05/31/81/carte_francaise_carreau_04/" data-orig-file="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_carreau_04.gif" data-orig-size="81,116" data-comments-opened="1" data-image-meta="{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}" data-image-title="Carte_française_carreau_04" data-image-description="" data-image-caption="" data-medium-file="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_carreau_04.gif?w=81" data-large-file="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_carreau_04.gif?w=81" class="alignleft size-thumbnail wp-image-2596" alt="Carte_française_carreau_04" src="https://justpuzzles.files.wordpress.com/2013/05/carte_franc3a7aise_carreau_04.gif?w=105&#038;h=150"   /></a></p>
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<p>Using exactly four fours, create the numbers 0-30. You may use the usual mathematical operands, but not squaring, as this requires a number 2. You may use brackets.<br />
Example: (4+4)-(4+4)=0</p>
<p>As always, please don&#8217;t publish your solutions. Solutions can be found after 1-2 weeks on the solution page for those who want to check their solutions, or for those who are really stuck.<br />
But scrolling is much easier, and really spoils the fun for others.</p>
<p>I am very much interested in your solution times, and I welcome your remarks and criticisms. Pointing out alternative solutions is also welcome, as they point out possible problems in the brain teasers.</p>
<p>If you are puzzled, we have a <a href="https://justpuzzles.wordpress.com/solutions-to-puzzles/#48">solution</a> for you.</p>
<p>This puzzle has a long history. When I still was a teenager, my father challenged me to make all numbers 0-20 using the digit 4 exactly 4 times. Recently I shared this puzzle with some fellow consultants. Kees Krol arrived at the office one morning and announced he had extended the range all the way to 30. 🙂</p>
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