A range of number challenges to test your brain, authored by Paul Godding, the board game and puzzle inventor and developed by NGfL Cymru.
There are four levels of difficulty to pit your wits against. How quickly can you complete the challenge?
Ddim yn gweld beth ydych eisiau? A oes yna broblem gyda'r ffeiliau? A oes gennych awgrym? Rhowch adborth i ni, rydym yn croesawu pob gohebiaeth gan ein defnyddwyr.