The grain store used to have (12/20) tons of rice, but after selling 500 kilograms, it shipped in (7/10) tons. How many tons of rice does the grain store have now?
粮店原来有(12/20)吨大米，卖出500千克后，又运进(7/10)吨，粮店现在有大米多少吨？
<gadget id="calculator">12 / 20</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">(3/5) - (1/2)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

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

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