uff, here it would be good if someone from galaxus who can distinguish points and commas and knows how to convert cm into metres would clarify the size of the individual puzzles. It is unlikely that the individual pieces have an edge length of 2.85 cm, which does not match the altes specification. 2.85cm is more the thickness. with nine pieces I can't get from 0 to 9, so there will probably be 10 puzzle pieces like in the photo. if the 32m is correct, you will get a square with an edge length of approx. 90cm and not 2.85 metres ....
So guessed and guessed. Now it would be nice if the PM corrects and clarifies the numbers ;-)

9 puzzle mats are available. 1 puzzle mat is 32x32cm. Thus, the assembled mat should be approximately 2.85 x 2.85 m.