What is the quotient of the difference between 0.9 and 0.6 divided by the sum of these two numbers?
0.9与0.6的差除以这两个数的和，商是多少？
<gadget id="calculator">0.9 - 0.6</gadget>
<output>0.3</output>

<gadget id="calculator">0.9 + 0.6</gadget>
<output>1.5</output>

<gadget id="calculator">0.3 / 1.5</gadget>
<output>0.2</output>

<result>0.2</result>