This card game is perfect integer practice for the students! (It is best played in pairs) The best thing is that you can vary the difficulty based on your student's level. Kids love the challenge and anything that has to do with playing cards!
Just print out the instructions and score cards for the students. I recommend laminating the score cards before giving to the students. This way they can use a dry/erase marker and you can re-use them each class/year.