A pen is 18 yuan, and a children's book is 4 yuan. Xiaohong bought a pen with 50 yuan, and the rest of the money is used to buy children's books. How many books can she buy?
一支钢笔18元，一本儿童读物4元．小红用50元钱买了一支钢笔，剩下的钱买儿童读物，可以买几本？
<gadget id="calculator">50 - 18</gadget>
<output>32</output>

<gadget id="calculator">32 / 4</gadget>
<output>8</output>

<result>8</result>