A bag of bread weighs (3/10) kg, how much does 7 bags weigh in kg?
一袋面包重(3/10)kg，7袋重多少kg．
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) * 7</gadget>
<output>21/10 = around 2.1</output>

<result>21/10 = around 2.1</result>