It is necessary to paint a wall that is 4 meters high and 6 meters wide in the classroom, and the area of the window is 7 square meters. How big is the area to be painted?
要粉刷教室里一面高4米、宽6米的墙壁，其中窗户的面积为7平方米，要粉刷的面积有多大？
<gadget id="calculator">4 * 6</gadget>
<output>24</output>

<gadget id="calculator">24 - 7</gadget>
<output>17</output>

<result>17</result>