In a stationery store, if the price of a product is higher than the purchase price (1/3), then the purchase price is much less than the purchase price.
某文具店，商品的标价比进货价提高(1/3)，则进货价比标价少多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 + (1/3)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">(1/3) / (4/3)</gadget>
<output>1/4 = around 0.25</output>

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