How much is the difference between the sum of 2.5 and 1.8?
2.5与1.8的和比它们的差多多少．
<gadget id="calculator">2.5 + 1.8</gadget>
<output>4.3</output>

<gadget id="calculator">2.5 - 1.8</gadget>
<output>0.7</output>

<gadget id="calculator">4.3 - 0.7</gadget>
<output>3.6</output>

<result>3.6</result>