After drinking (1/2) of a glass of milk for the first time, fill it up with water and drink (1/2) of it again, how many cups of pure milk do you drink twice?
一杯牛奶，第一次喝去(1/2)后，加满水又喝去它的(1/2)，两次共喝纯牛奶多少杯？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * (1/2)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/2) + (1/4)</gadget>
<output>3/4 = around 0.75</output>

<result>3/4 = around 0.75</result>