Today we're celebrating the 40th birthday of the Rubik's Cube, a 3D combination puzzle game with 43 quintillion combinations that tests memory, spatial reasoning and critical thinking.

Widely considered to be the world's best-selling toy, the Rubik Cube was invented by Hungarian architecture professor Ernő Rubik.

The puzzle was most popular in the 1980s, but thanks to a revival, there is now a World Cube Association governing Rubik's Cube competitions and keeping official world records that "speedcubers" around the world struggle to beat.

Solving the Rubik's Cube can be quite challenging and frustrating, but if you'd like to improve your ability to solve the puzzle, check out some handy video how-tos we've compiled, together with the solution to the Rubik's Cube Google Doodle:

1. How to solve the Rubik's Cube Google Doodle

It would be better if you tried this out yourself, but if you get stuck after a while, YouTube user Simon Reuger, better known as Google Doodle Collection has come up with a handy solution video:

2. Beginner's tutorial to solving a Rubik's Cube

YouTube user TheSergsB has a popular channel on the video-sharing website that specialises in Rubik's Cube tutorials. His "simplest tutorial" has over 2 million views and he breaks down the strategies needed to solve the puzzle:

3. Fridrich's method to solving the Rubik's Cube

Jessica Fridrich, a Binghamton University professor, developed the CFOP method in 1982, which is the most popular method for speed-solving the Rubik's Cube. Her method takes 17 seconds and you can view instructions here or watch the following video tutorial by YouTube user lucatn:

4. How to solve the Rubik's Cube in five simple moves

If you'd like to solve the Rubik's Cube in just five moves, following a specific strategy that can help you improve your completion time, check out VinceRocca's video tutorial, which explains how to solve the puzzle step-by-step without confusing you with algorithms:

5. Watch this 3-year-old solve the Rubik's Cube in just under three minutes

Finally, to inspire yourself, watch 3-year-old Emily Gittemeier. Her family are speed-solving Rubik's Cube lovers (known as "speedsolvers") and she learned how to solve the puzzle by herself, just by copying her older brother's movements: