Building Arrays

Lets build an array with four rows.  Each row needs to have three students in it.  I ask students to come forward and build an array with their bodies, as you can see in this picture of my students.  When finished ask students:  How many rows does this array have?  How many columns does this array have?  How many total students are in this human array?

An array is a way to arrange items so that we can easily count them.  Let’s try to make another human array.   Let’s make an array with two rows of five students. I ask students to come forward and build an array with their bodies.  When finished ask students:  How many rows does this array have?  How many columns does this array have?  How many total students are in this human array

Now that we have built arrays with our classmates we’re going to build arrays using counters. Hand out counters to students. On your white board build an array that has three rows of five.

When finished ask students:  How many rows does this array have?  How many columns does this array have?  How many total students are in this human array.

Depending on time, student engagement, and student understanding, do 2-5 more practice problems using counters.  Make sure that students are able to explain how many of each item are in each row and how many are in each column. 

Today we built arrays using our bodies, our counters, and our brains (when we drew out our arrays). Tomorrow we will start to use number sentences to describe our arrays!