Pack a batch of candies, plan to pack 40 pieces in each box, and need to pack 15 boxes. Now there are only 12 boxes. If you want to pack all these candies, how many more pieces of candy will each box hold than planned on average?
分装一批糖果，计划每只盒子装40块，要装15盒，现在只有12只盒子，要把这些糖装完，平均每只盒子比计划多装多少块糖？
<gadget id="calculator">15 / 12</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">40 * (5/4)</gadget>
<output>50</output>

<gadget id="calculator">50 - 40</gadget>
<output>10</output>

<result>10</result>