What is the area of a square with side length 4 cm less than the area of a square with side length 5 cm?
边长4厘米的正方形面积比边长5厘米的正方形面积小多少．
<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">25 - 16</gadget>
<output>9</output>

<gadget id="calculator">9 / 25</gadget>
<output>9/25 = around 0.36</output>

<result>9/25 = around 0.36</result>