In a subtraction expression, the minuend is increased by 1.8 and the subtrahend is decreased by 1.8. How much does the difference increase?
在一个减法算式中，被减数增加1.8，减数减少1.8，差增加多少
<gadget id="calculator">1.8 + 1.8</gadget>
<output>3.6</output>

<result>3.6</result>