There was a download of Addition & Subtraction 1.7 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. Addition & Subtraction lies within Education Tools, more precisely Science Tools.
The following version: 1.7 is the most frequently downloaded one by the program users. This program is an intellectual property of School Zone Interactive.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. Commonly, this program's installer has the following filename: 10307_7.exe. The software is sometimes distributed under different names, such as "Addition Subtraction".
From the developer:
Flash Action Addition & Subtraction transforms your computer into a fast, fun, fact machine that makes learning addition and subtraction child's play. Children practice problems against the clock, challenge another player to a game of fast facts or test themselves for speed and accuracy. Set the program to practice addition, subtraction or mixed problems, and the difficulty will be adjusted based on your child's score.
You may want to check out more software, such as Grey Olltwit's Maths Worksheet - Subtraction, Free Learn Addition on Orbital One or Grey Olltwit's Maths Worksheet - Addition, which might be related to Addition & Subtraction.