A javascript based math game about summing to zero.
Try it out online at https://pensivetoucan.github.io/Zero-Sum/.
Also available for Android on Google Play - Zero Sum.
Highlight sequences of numbers that sum to zero. The longer the sequence, the more points it's worth. Get as many points as you can in 60 seconds.
Click a number to start the sequence. Extend the sequence by clicking on a number that is adjacent (row-wise or column-wise) to any number already in the sequence. Click outside the number grid to clear the sequence.