Matrix Abacus Calculator is very nice program for working and computing with math matrices. It is able to perform basic math operation, but it can solve for example linear equations. All working in very nice GUI and transparent representation of the relationships between parent-child matrices. Only download it - and without any installation run it only.
Supported areas: Matrix Transposition. Matrix Inversion. Matrix Opposition. Determinant of the matrix, rank of the matrix. Scalar matrix operations: Addition, subtraction, multiplication. Two matrices operations: Addition, subtraction, multiplication. Solving of linear equations. Other features: Working with real and fraction numbers ! Graphical interface (GUI). Transparent relationships between matrices in the model. Load/save support, Excel copy/paste support. Data import/export/saving into image. Global settings. Model and data printing with print preview support. User guide and basic step-by-step tutorial (*.pdf). Only for 8.99 Euro (14 days for trying free).