Math4Office is a powerful and easy to use math equations checker and expressions solver. 

The Google Docs add-on enables users to easily check their math and scientific expressions right inside google Docs. 

Just click the "Check" and E"valuate" buttons from the Math4Office add-on sidebar. You can also use the Calculator section to perform side calculations. 

In addition to regular expressions, Math4Office also supports expressions with complex algebraic and scientific expressions, including units, constants, variables, functions, vectors, and matrices.