Aunt Li bought a fresh shiitake mushroom with a moisture content of 99%. After drying, the moisture content dropped to 98%, so the weight was reduced by 490 grams. What was the weight of the fresh shiitake mushroom when she first bought it?
李阿姨买一种鲜香菇，含水率是99%，经晾晒后含水率下降到98%，因此质量减少了490克，开始买来时鲜香菇的质量是多少克．
<gadget id="calculator">99 / 100</gadget>
<output>99/100 = around 0.99</output>

<gadget id="calculator">1 - (99/100)</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">(99/100) / (1/100)</gadget>
<output>99</output>

<gadget id="calculator">98 / 100</gadget>
<output>49/50 = around 0.98</output>

<gadget id="calculator">1 - (49/50)</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">(49/50) / (1/50)</gadget>
<output>49</output>

<gadget id="calculator">99 - 49</gadget>
<output>50</output>

<gadget id="calculator">490 / 50</gadget>
<output>49/5 = around 9.8</output>

<gadget id="calculator">(49/5) / (1/100)</gadget>
<output>980</output>

<result>980</result>