There are 500 grams of 3.2% salt water, how many grams of salt need to be added in order to make it into 20% salt water?
有3.2%的食盐水500克，为了把它制成20%的食盐水，需要再加多少克的食盐？
<gadget id="calculator">3.2 / 100</gadget>
<output>0.032</output>

<gadget id="calculator">1 - 0.032</gadget>
<output>0.968</output>

<gadget id="calculator">500 * 0.968</gadget>
<output>484</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">484 / (4/5)</gadget>
<output>605</output>

<gadget id="calculator">605 - 500</gadget>
<output>105</output>

<result>105</result>