You are downloading the PG-Calculator XAP file v188.8.131.52 for Windows Phone. PG-Calculator is a free and useful Education app: This little application can solve simple equations, prime factorialize, decide if the number is prime or not (up to 6 digit numbers), solve ... You can now download the offline XAP file to install & try it.
Download Locations for PG-Calculator 184.108.40.206 XAP file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline XAP File To Install It Any More.
To try to install it manually from an SD card, you should choose one of the server location above to get the offline PG-Calculator XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.