Worked like a charm out of the gate.  Great little step up after WeDo, Scratch and beginning coding! 

Download File

~$  cd /home/pi/{downloaded folder}
~$  sudo dpkg -i S4A15_RP.deb

• Now if you open the start menu and go to Programming, there should be S4A in the list. Click on it to start Scratch for Arduino.

• Of course we also need an Arduino to program on. This Arduino needs to be prepared for S4A by loading a specific ‘sketch’ (an Arduino code file) onto it. This file can also be found HERE.
• If you have access to a computer with the Arduino software already installed, it is easiest to do it from there. Open and upload the file to your Arduino as a regular Arduino code.
• Note that not all Arduino’s work well with Scratch for Arduino. Currently only the Arduino Diecimila, Duemilanove and Uno are tested.

• When you start S4A you will see a drawing of an Arduino already loaded as a sprite.
• It will automatically search for the Arduino. If this does not find it, right click on the sensor board (the list with all the blue values) and select “stop searching board”.
• Right click it again and click “Select Serial/USB-port”. Then there should pop up a little menu where you can select the port of your connected Arduino.

http://nielsswinkels.nl/2014/interaction-design/how-to-install-scratch-for-arduino-s4a-on-raspberry-pi/