Both Honghong and Mingming have 20 cartoon books. After Honghong gives Mingming 5 books, how many books will Honghong have less than Mingming?
红红和明明都有20本卡通书，红红给明明5本后，红红就比明明少多少本？
<gadget id="calculator">20 + 5</gadget>
<output>25</output>

<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<gadget id="calculator">25 - 15</gadget>
<output>10</output>

<result>10</result>