Cut out the largest square from a rectangle with a length of 100 cm and a width of 80 cm, what is the remaining area in square centimeters?
从一个长100cm，宽80cm的长方形上剪下一个最大的正方形，剩下的面积是多少平方厘米．
<gadget id="calculator">100 * 80</gadget>
<output>8_000</output>

<gadget id="calculator">80 * 80</gadget>
<output>6_400</output>

<gadget id="calculator">8_000 - 6_400</gadget>
<output>1_600</output>

<result>1_600</result>