What is the difference between twice the opposite of 8 minus half the reciprocal of -2?
8的相反数的2倍减去-2的倒数的一半的差是多少．
<gadget id="calculator">63 / 4</gadget>
<output>63/4 = around 15.75</output>

<result>63/4 = around 15.75</result>