Roll a die several times, recording the numbers rolled. Ask students to find the sum of the numbers rolled. Ask if the sum will be different if the numbers are added in a different order.

Give students problems such as the following:

           2 + 3 =           3 + 2 =       23 + 24 =       24 + 23 =

       18 + 17 =       17 + 18 =           5 + 3 =           3 + 5 =

Ask the students if they notice any similarities in the answers to the problems. Discuss the commutative property of addition.

Problem:

Fill in the table below using five counters and a handout with two shapes. Place the counters on the shapes to find the missing numbers.