Illuminations: Let's Learn Those Facts

# Let's Learn Those Facts

In this unit, students who have previously studied the meanings of addition use the properties of addition to help them learn addition facts and to master the addition tables. The unit is most appropriate for students of grades 1 and 2. The ability to name the sum of two one-digit numbers with speed and accuracy is an important accomplishment. This skill allows students to focus on multistep algorithms and to compute the answers to problems.

Addition properties explored in this unit include the order property, the additive identity, and the results of adding by zero. The most effective and efficient way to help students learn addition facts is to help them build an understanding of the operation, encourage them to use the helpful features of the number system, and give them interesting activities that foster retention.

### Individual Lessons

Lesson 1 - Finding Addition Patterns

A game encourages students to find the sums of two one-digit numbers. Students explore commutativity and examine addition patterns. Then they record known facts on a personal addition chart.

Lesson 2 - Finding Sums to Six

In this lesson, students discover the role of the additive identity and explore sums to six. They continue to complete their personal addition charts.

Lesson 3 - Some Special Sums

Students practice doubles and doubles-plus-one addition facts. They record their current level of mastery of the addition facts on their personal addition charts.

Lesson 4 - Addend Pairs to 12

Students practice their addition facts for sums up to 12 by playing a game. They add to their personal addition charts. Students are encouraged to practice the facts that they have not yet mastered. Finally, triangular flash cards help students practice addition facts.

Lesson 5 - Wrapping up the Unit

In this final lesson of the unit, students display their knowledge of properties of objects for sorting and creating patterns. They also demonstrate an understanding of commutativity and model addition and subtraction of whole numbers using different representations.

### NCTM Resources

 More and Better Mathematics for All Students
 © 2000 National Council of Teachers of Mathematics Use of this Web site constitutes acceptance of the Terms of Use The National Council of Teachers of Mathematics is a public voice of mathematics education, providing vision, leadership, and professional development to support teachers in ensuring mathematics learning of the highest quality for all students. The views expressed or implied, unless otherwise noted, should not be interpreted as official positions of the Council.