 Deception and problem solving are central themes in this novel as both the thief and the central adult players use a variety of ways to hide the truth while the children employ a series of mathematical and problem @-@ solving concepts to piece together the clues to the puzzle . In addition , Calder and Petra develop a special friendship and certain respect for the value of art . 
 Deception and problem solving <a href='drop_aux' title='1'><mark>are</mark></a>central themes in this novel as both the thief and the central adult players use a variety of ways to hide the truth while the children employ a series of mathematical and problem @-@ solving concepts to piece together the clues to the puzzle . In addition , Calder and Petra develop a special friendship and certain respect for the value of art . 
Deception and problem solving central themes in dis novel as both the thief and the central adult players use a variety of ways to hide da truth while tdachildren employ a series of mathematical and problem @-@ solving concepts to piece together the clues to thdauzzle . In addition , Calder and Petra develop a special friendship and certain respect fir thedalue of art .