You are downloading the MathsFormulas AppX file v184.108.40.206 for Windows Phone. MathsFormulas is a free Education App: MathsFormulas is the Source of all maths formulas. MathsFormulas is Covering almost all maths formulas with interactive graphics format.Many Places. You can now download the offline AppX package file to install & try it.
Download Locations for MathsFormulas 220.127.116.11 AppX file
To try to install it manually from an SD card, you should choose one of the server location above to get the offline MathsFormulas AppX file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.