A bottle of shampoo was used for a week, about 1/4 of the total amount was used. After half a month, the rest (2/3) was used up. What fraction of the total amount of shampoo was used in the past half month?
一瓶洗发水用了一个星期，大约用去总量的(1/4)．过了半个月，又大约用去了剩下的(2/3)．这半个月用去的是洗发水总量的几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(3/4) * (2/3)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>