Calculation: (10/21)-(3/7)+(2/3).
计算：(10/21)-(3/7)+(2/3)．
<gadget id="calculator">10 / 21</gadget>
<output>10/21 = around 0.47619</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(10/21) - (3/7)</gadget>
<output>1/21 = around 0.047619</output>

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

<gadget id="calculator">(1/21) + (2/3)</gadget>
<output>5/7 = around 0.714286</output>

<result>5/7 = around 0.714286</result>