The decoration workers have to paint the classrooms. The painting area is 216 square meters. If the painting cost per square meter is 18 yuan, how much will it cost to paint this classroom?
装修工人要粉刷教室．粉刷面积是216平方米，如果每平方米的粉刷费用是18元，粉刷这间教室要花多少钱？
<gadget id="calculator">18 * 216</gadget>
<output>3_888</output>

<result>3_888</result>