Mom gave Xiao Ming a big box, which contained 3 cardboard boxes, and each cardboard box contained 3 small boxes. How many boxes does Xiao Ming have in total?
妈妈给小明一个大盒子，里面装着3个纸盒子，每个纸盒子又装3个小盒子，小明一共有多少个盒子．
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">9 + 3 + 1</gadget>
<output>13</output>

<result>13</result>