Teacher presentation materials. Unit: 2.8 Equal Groups (Grade 2). 2.8 Equal Groups Unit Goals Students work with equal groups of objects to gain foundations for multiplication. Section A Goals Determine whether a group of objects (up to 20) has an odd or even number of members. Write an equation to express an even number as a sum of two equal addends. Section B Goals Find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns using addition. Partition rectangles into rows and columns of equal-size squares, and count to find the total number of squares. Represent the total number of objects in an array as a sum of equ