The mass of salt is 5 grams, and the mass of water is 20 grams. If you want to prepare 12 grams of such brine, how many grams of salt are needed?
盐的质量是5克，水的质量是20克，如果要配制这样的盐水12克，那么需要盐多少克？
<gadget id="calculator">5 * 12</gadget>
<output>60</output>

<gadget id="calculator">5 + 20</gadget>
<output>25</output>

<gadget id="calculator">60 / 25</gadget>
<output>12/5 = around 2.4</output>

<result>12/5 = around 2.4</result>