Triangle Fact Families
Many teachers use the triangle facts to practice addition and subtraction facts. The beauty of these cards, as opposed to traditional flash cards, is that each card has the three numbers of a fact family. By varying what number the teacher covers, the same card can be used for addition or subtraction fact practice. Note that the larger number is at the top of the triangle.
Individual practice: Give each student a triangle card(s) and ask them to use that card to write four number sentences for that fact family. Students may exchange cards after their work is checked for accuracy.
Challenge: Write in only two of the three numbers and challenge students to figure out the third number and then write the four number sentences for that fact family. Be sure to have students explain how they figured out the missing number as this increases the problem-solving repertoire of all students in the class.