These thematic pictures of Μαθηματικά are analogous to a visual dictionary. The theme "Μαθηματικά" is split into several parts. For children, especially toddlers from 1 to 5 years old, it is better to divide the sets of cards over several days, or even weeks, so that the information is absorbed better. This is especially true if you are using flashcards to learn greek language that is not your native language.
To expand your greek language vocabulary on the "Μαθηματικά" topic, flashcards games are the best way: