Arithmetic game for little kids

Playable online here: https://jbergknoff.github.io/arithmetic

Attribution

• Success sound from https://freesound.org/people/grunz/sounds/109662/
• Failure sound from https://freesound.org/people/KevinVG207/sounds/331912/
• Icon font generated by https://icomoon.io/ from SVGs that I created.