My family has been enjoying Tang Math card games. I purchased two sets, “Home Kit Jr.” for K–2 and “Home Kit Sr.” for grades 3–5. (You can also buy the decks singly, but I think that’s a bad deal.) These are great as math exercises; they are less fun but okay as games.
The basic idea of Kakooma is to look at a grid of five or nine numbers and find two numbers than sum (or multiply) to a third. Numtanga shows numbers or values written in different ways; the idea is to find matching numbers on two different cards.
My favorite game is Expresso. A card shows four numbers. You role a die. Then, using two to four of the numbers (or three or four of the numbers with the harder cards), you figure out a way to add, subtract, multiply, or divide to reach the value on the die. This can get quite challenging.
What we did is just go around in a circle with everyone taking a turn solving an Expresso puzzle. You can also make this competitive my seeing who can find a successful solution first, but generally that would favor the person fastest at finding such patters, so I don’t think that would be much fun.
Here’s another way to make the game harder and more competitive: Take turns, but each player tries to find as many solutions for each card and die roll as possible. Then, the player with the most successful solutions wins the card. In cases of a tie, the person whose turn it is (or who is next in line) wins the tie.