The soldier miscalculated 4*(□+(5/2)) into 4*□+(5/2), and the calculated result was much less than the correct result.
小兵把4*(□+(5/2))错算成4*□+(5/2)，算出的得数比正确得数少多少．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">10 - (5/2)</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>