After Xiao Gang gave his younger brother 4 exercise books, he still had 2 more exercise books than his younger brother. It turned out that his younger brother had fewer exercise books than Xiao Gang.
小刚送给弟弟4个练习本后，还比弟弟多2个练习本，原来弟弟比小刚少多少个练习本．
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<result>10</result>