bottle of water, drink its (3/10), then pour this bottle of water (1/10). How much water is in the bottle now?
一瓶水，喝了它的(3/10)，又倒入这瓶水的(1/10)．现在瓶子里的水有多少？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(7/10) + (1/10)</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>