MATRIS 4.11.0515 was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The actual developer of the software is Jutta Behling. The program lies within Education Tools, more precisely Science Tools.
The MATRIS installer is commonly called ACC.exe or matris.exe etc. We cannot guarantee that the program is safe to download as it will be downloaded from the developer's website. Before launching the program, check it with any free antivirus software. The following versions: 4.1, 3.1 and 1.3 are the most frequently downloaded ones by the program users.
From the developer:
MaTris lets your child practice basic arithmetic. Exercises include counting symbols, addition, subtraction, division, and multiplication. A wizard lets you adjust the duration and content of each session, and it lets you set up a log file to track results. As each question is answered correctly, a spider drops down a wall.
You may want to check out more software, such as f x -Viewer, Trachtenberg Speed Math or Pocket Stars, which might be related to MATRIS.