If x is 30% less than 300 and y is 30% more than x, then x+y=how much.
x比300少30%，y比x多30%，则x+y=多少．
<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">300 * (7/10)</gadget>
<output>210</output>

<gadget id="calculator">1 + (3/10)</gadget>
<output>13/10 = around 1.3</output>

<gadget id="calculator">210 * (13/10)</gadget>
<output>273</output>

<gadget id="calculator">210 + 273</gadget>
<output>483</output>

<result>483</result>