basket of apples has already eaten 38 apples. If you eat 4 apples a day, you can still eat them for 13 days. How many apples are there in this basket?
一筐苹果，已经吃了38个，剩下的如果每天吃4个，还可以吃13天．这筐苹果一共有多少个？
<gadget id="calculator">4 * 13</gadget>
<output>52</output>

<gadget id="calculator">52 + 38</gadget>
<output>90</output>

<result>90</result>