A box of biscuits, eat (1/3), and there are (3/5) kilograms left, how many kilograms are there in this box of biscuits?
一盒饼干，吃掉(1/3)，还剩(3/5)千克，这盒饼干原有多少千克？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(3/5) / (2/3)</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>