A steel wire is 3 decimeters long, and 5 centimeters are used up, how many centimeters are left?
一根钢丝长3分米，用去5厘米，还剩下多少厘米？
<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">30 - 5</gadget>
<output>25</output>

<result>25</result>