1.8 How much is the sum of 4.9 and 6.5 less than 7.5? What is the column formula?
1.8除4.9与6.5的和比7.5少多少，列式为多少
<gadget id="calculator">4.9 + 6.5</gadget>
<output>11.4</output>

<gadget id="calculator">11.4 / 1.8</gadget>
<output>6.333333</output>

<gadget id="calculator">7.5 - 6.333333</gadget>
<output>1.166667</output>

<result>1.166667</result>