These fun Christmas math Boom Cards are for subtraction facts within 20. They are a great way to celebrate Christmas in math time. There are 22 cards for subtraction facts within 20. In this deck, the children decorate the Christmas tree by dragging the ornaments with the facts that equal the answer on the card to the tree. This is a fun way to practice subtraction facts, making it an ideal activity for first grade, second grade or third grade or those who need to work on developing subtraction