From https://www.howweelearn.com/teaching-math-preschoolers-playing-cards/

To play this cards games for kids you simply need playing cards (ex. UNO cards or... actually, any deck will work.)

In a nutshell:

Each player begins with 5 cards in front of them, facing up

The first (youngest) player makes any pairs they can from their 5 cards. Next, that first player makes any pairs they can with the addition of the second player's cards. When no more pairs can be made, it is the second player's turn.

The second player chooses cards from the deck until s/he has 5 cards. S/he makes any pairs s/he can, and then makes any pairs s/he can with the addition of the first player's cards...

Continue until no more pairs can be made. Students need to be able to say the names of the numbers in ENGLISH (but they can get help by asking). The next player can NOT take their turn until the first player has finished naming the pairs of numbers in English.

You can simplify this game by only using the cards with numbers from 1-5 or whatever. To avoid confusion, pull out all specialty cards such as: draw two, skip a turn, or aces, jacks, queens, and kings from regular card decks before you begin. 

As a review, have the players put the pairs in order from lowest to highest, naming them as they go.