Luke started working on a 1000-piece jigsaw puzzle. The first day he worked on it, he put together 10% of the pieces. On the second day, he put together another 20% of the remaining pieces from the first day. On the third day, he put together 30% of the remaining pieces from the previous day. How many pieces does he have left to complete after the third day?
Luke started putting together, 1000 x 0.1 = 
<gadget id="calculator">1000*0.1</gadget>
<output>100</output>
100 pieces.
The next day, there were 1000-100 = 
<gadget id="calculator">1000-100</gadget>
<output>900</output>
900 pieces left.
Then he put together 900 * 0.2 = 
<gadget id="calculator">900*0.2</gadget>
<output>180</output>
180 pieces on the second day.
So there were 900 - 180 = 
<gadget id="calculator">900-180</gadget>
<output>720</output>
720 pieces left.
On the third day, he put together 720 * 0.3 = 
<gadget id="calculator">720*0.3</gadget>
<output>216</output>
216 pieces.
Therefore, Luke still has 720 - 216 = 
<gadget id="calculator">720-216</gadget>
<output>504</output>
504 pieces left to complete the puzzle.

<result>504</result>