A glass of 250ml of fresh milk contains (3/10) g of calcium, which accounts for (3/8) of an adult's daily calcium needs. How much calcium does an adult need per day?
一杯250ml的鲜牛奶含有(3/10)g的钙质，占一个成年人一天所需钙质的(3/8)．一个成年人一天需要多少钙质？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(3/10) / (3/8)</gadget>
<output>4/5 = around 0.8</output>

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