Xiaoli's storybooks belong to all her collections (2/5). After buying 2 more storybooks, the storybooks are all her collections (1/2). How many books does she have now?
小丽的故事书是她所有藏书的(2/5)，又买了2本故事书后，故事书是她所有藏书的(1/2)，现在她有几本书？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 2</gadget>
<output>1</output>

<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / (1/10)</gadget>
<output>10</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<result>12</result>