This card game is sure to put a smile on your students' faces this holiday season. Modeled after the card game War, students will partner up and make two piles of Christmas Elf cards. They will flip over the top card of their piles at the same time and solve the three number addition problem. The student with the greater sum will collect both cards. When both student card piles are gone the game is over and the student with more cards wins! There is even a worksheet to follow up the game and solidify your students' understanding of adding with three numbers. All sums are within 20.