Does this running of 5+5 take a long time just once, then MATLAB is sufficiently fast for the rest of the session? If so, are you making sure to wait until MATLAB is done "Initializing" before you enter code or try to do anything?
If MATLAB is slow every time you enter a command to run during a session, then it could be that MATLAB is having trouble finding your license, or is otherwise slow during your license check. Try out "Solution 1" in the answer here. Despite being for an older version of MATLAB, the specification of the license file with "-c" is still applicable, though the license file itself may have changed depending on your version (.lic now, I believe). Depending on your version of Windows (I'm assuming Windows here), it's also worth checking out if compatibility mode can help (as mentioned here).
If all that still isn't doing it, can you give us which MATLAB release you have installed, which OS you are using, and if this is a new problem with an old installation, or if MATLAB has always been this way on this machine?