What is the concentration of salt water obtained by dissolving 15 grams of salt in 45 grams of water?
将15克盐溶解在45克水中，则所成盐水的浓度为多少．
<gadget id="calculator">15 + 45</gadget>
<output>60</output>

<gadget id="calculator">15 / 60</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(1/4) * 1</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>