The shopping mall celebrated its 10th anniversary, and put 1,000 balloons on the square of the mall, 20% of which were damaged within one week, 30% were damaged in the second week, and 50% were damaged in the third week. In order to ensure the number of balloons on the square, Every weekend the mall replaces damaged balloons with new ones. How many new balloons will be replaced on the weekend of the third week?
商场庆祝开业10周年，在商场的广场上放了1000个汽球，其中20%在一周内损坏，30%在第二周损坏，50%在第三周损坏，为了保证广场上气球的数量，每个周末商场都会将损坏的气球换成新的气球．问第三周周末共要换上多少个新气球？
<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">1_000 * (4/5)</gadget>
<output>800</output>

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

<gadget id="calculator">800 * (3/10)</gadget>
<output>240</output>

<gadget id="calculator">1_000 * (1/5)</gadget>
<output>200</output>

<gadget id="calculator">200 * (1/5)</gadget>
<output>40</output>

<gadget id="calculator">240 + 40</gadget>
<output>280</output>

<gadget id="calculator">200 * (4/5)</gadget>
<output>160</output>

<gadget id="calculator">160 * (3/10)</gadget>
<output>48</output>

<gadget id="calculator">280 * (1/5)</gadget>
<output>56</output>

<gadget id="calculator">280 + 48 + 56</gadget>
<output>384</output>

<result>384</result>