You are downloading the MathRush XAP file v188.8.131.52 for Windows Phone. MathRush is a free and useful Education app: Exercise those grey cells with some fun arithmetic. Spend 60 seconds answering as many questions as you can and figure out how you stack against the ... You can now download the offline XAP file to install & try it.
Download Locations for MathRush 184.108.40.206 XAP file
Note: To install it manually from an SD card, you should choose one of the server location above to get the offline MathRush XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.