## October 30, 2014

### Exploring 2-Digit Multiplication with Base Ten Blocks

Guest Blog Post by Dr. Shirley Disseler

The way we do math has changed! The Common Core offers a new way to look at an old subject and encourages us to integrate relevant content. There are many new and exciting ways to get students motivated in the math by teaching in this more constructivist manner. For example, manipulatives like base ten blocks can be used to create area models of multiplication. This method’s focus is based on place value, which is an area of great importance for elementary students if they are to master math concepts in later years. Many teachers are just not comfortable with this new format, so I would like to describe an activity to get students comfortable with the new way to use place value to multiply two-digit numbers using manipulatives.

First the teacher should provide a hands-on practice time so that students begin to get comfortable with the manipulatives. To do that students should be given base ten blocks and provided a problem such as 12 x 14. Students then build the model and write the partial products. Students would draw the model and explain where the partial products portion of the model. It would look like this:

This approach is optimal for students because engagement is ramped up. Students do not realize they are really practicing multiplication of 2 digit numbers, and it affords the teacher the time to walk around and assess the level of struggle going on among students.

Area Model Match-Up Freebie
Once students have begun to understand students can begin to investigate the topic in more of game-like format using the Area Model Match-Up Activity, a lesson included in my book Strategies and Activities for Common Core Math Grades 3-5, Part I. My publisher has allowed me to share this activity as a free download. Click the image on the right to download it and read the complete directions.

In this activity, students play in groups of 2 or 3 to draw a two-digit multiplication problem card. Each student models the problem using base ten blocks and the others try to identify the problem and create a solution. Area Model Match-Up covers the standards included in Numbers in Base Ten for grades 4 & 5, as well as many of the math practices of the current standards. This strategy provides a more hand-on approach to understanding the actual number placement in two-digit multiplication problems. It takes out the misconception that students often have about the zero that serves as a place holder in this computational skill.

Math will always be about numbers, but the fact that students now need to “know” the math, not just “do” the math somehow makes it more fun. At the same time, it makes it somewhat scary for those teachers who did not learn to teach in this way.  Try these activities and see how engaged the students become!  Enjoy and remember… Common Core brings the “do” and the “know” together!

Dr. Shirley Disseler is Assistant Professor of Elementary and Middle Grades Education at High Point University in North Carolina. She has National Board certification as a Middle Childhood Generalist. Dr. Disseler has taught both elementary and middle school math and science, and has received many awards throughout her teaching career. She is the author of Strategies and Activities for Common Core Math Grades 3-5, a 2-part series.