There are 630 kilograms of white sugar and brown sugar in the Happy Food store, of which brown sugar accounts for 20%. Later, some brown sugar is shipped in. At this time, brown sugar accounts for 30% of the total weight of the two sugars. How many kilograms of brown sugar were transported later?
快乐食品商店有白糖和红糖630千克，其中红糖占20%，后来又运进一些红糖，这时红糖占两种糖总重量的30%．后来运进红糖多少千克？
<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">630 * (4/5)</gadget>
<output>504</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">504 / (7/10)</gadget>
<output>720</output>

<gadget id="calculator">720 - 630</gadget>
<output>90</output>

<result>90</result>