Plusris

Plusris is a simple, addictive one-finger brain-training puzzle. Trace the numbers with your finger, add them to 10, and erase them to clear the board. The rules are easy, yet the puzzles range from easy to difficult, keeping your mind sharp.

With a massive library of problems—15,000 base questions, plus daily and weekly challenges (an additional 32,000)—you can practice anytime. Hints are available for difficult problems, but not for weekly challenges; check our SNS for tips and strategies.