The new semester started, and his mother gave Wangzai some money to buy homework books. Wangzai first bought a few notebooks, and there was still 10 yuan left, and then he wanted to buy 3 more notebooks, but found that 2 yuan was missing. Money, how much is the price of each exercise book?
新学期开始了，妈妈给了旺仔一些钱，让他去买作业本，旺仔开始买了几个本子，还剩下10元钱，然后他想再买3个本子，结果发现缺2元钱，每个作业本的价格是几元钱？
<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<result>4</result>