The base of a triangle is 40 decimeters, and the height is half of the base. What is the area of the triangle in square meters?
一个三角形的底是40分米，高是底的一半，这个三角形的面积是多少平方米？
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 / 2 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">40 * (1/10)</gadget>
<output>4</output>

<result>4</result>