A rectangular TV screen has a length of 7 decimeters and a width of 4 decimeters. What is the area of the TV screen in square decimeters?
一台长方形的电视机屏幕长7分米，宽长4分米，这个电视机屏幕的面积是多少平方分米？
<gadget id="calculator">7 * 4</gadget>
<output>28</output>

<result>28</result>