You could have downloaded zerosum 1.0 from our software library for free. The following version: 1.0 was the most frequently downloaded one by the program users. The program's installer is commonly called ZEROSUM.EXE. The actual developer of the free program is Ihsan. Zerosum relates to Games.
From the developer:
ZeroSum puzzle is played on a square grid filled with numbers and +- signs. The objective of this game is to make a given sum of numbers by navigating through a grid of numbers and associated +- signs. Can use 5x5 grid for young children and 9x9 for experts with a lots of visual thinking.
You may want to check out more software, such as Christmas Quest, Firewoks Extravaganza or Sudoku XL-Solver, which might be related to zerosum.