Start with the total number of pencils and subtract the short ones.<br><br>
&bull; Total pencils = 9<br>
&bull; Short pencils = 6<br>
&bull; Longer pencils = 9 &minus; 6 = 3<br><br>
3 pencils are longer.<br>
Check: 6 + 3 = 9 &#10003;