\begin{wrapfigure}{r}{2.6in}
\begin{centering}
- \includegraphics[width=2.6in]{figures/scratch_screenshot_default.png}
+ \includegraphics[width=2.6in]{figures/scratch_screenshot_default.jpg}
\caption{A screenshot of the Scratch programming environment
where users create animations and interactive games.}
\label{fig:scratchapp}
\begin{wrapfigure}{l}{2.6in}
\vspace{-1em}
\begin{centering}
- \includegraphics[width=2.6in]{figures/frontpage_modified-topremix.png}
+ \includegraphics[width=2.6in]{figures/frontpage_modified-topremix.jpg}
\caption{The front page of the Scratch online community where users
can share and collaborate on projects.}
\label{fig:scratchfrontpage}
\begin{wrapfigure}{r}{0.25\textwidth}
\vspace{-1em}
\begin{centering}
- \includegraphics[width=1.5in]{figures/lilypad.png}
+ \includegraphics[width=1.5in]{figures/lilypad.jpg}
\caption{A image of the LilyPad Arduino microcontroller.}
\label{fig:lilypad}
\end{centering}