Grade Levels: 3-5, 6-8

In this lesson plan, which is adaptable for grade 3 through 8, students use BrainPOP resources to understand and apply the associative property. Students will use an online interactive game to practice rounding strategies and adding numbers in different combinations to create a target amount.

Lesson Plan Common Core State Standards Alignments

Students will:

  1. Understand and apply the associative property.
  2. Understand and apply rounding strategies.
  3. Practice adding numbers in different combinations to create a target amount.


  • Computers and internet access
  • Standard playing cards or other numbered cards (one set for each pair of students)
  • Projector and interactive whiteboard


This lesson plan features an Illuminations game called Deep Sea Duel. Okta the Octopus plays students in a game in which the first person to choose cards with a specified sum wins. You can choose how many cards, what types of numbers, and Okta's level of strategy. Okta is a smart octopus, so you may want all students to start with only 9 cards and keep Okta's skill level set to easy!

When you show students how to play the game, point out that the target sum is in the lower left hand corner, and emphasize that ANY three cards drawn can add up to the target, so even if your initial sum goes over the target number, you can still win. For example, if the target sum is 15 and the cards you choose are 4,5,9, and 2, the game will automatically calculate that 9+4+2=15. It will discount the 5 you selected and announce that you've won the round.

Lesson Procedure:

  1. Build background knowledge about adding numbers and the associative property by playing the Associative Property movie on BrainPOP.
  2. Display the Q&A and challenge students to answer the questions about the associative property in a class discussion.
  3. Project the Deep Sea Duel game for the class to see. Show the initial directions screen and play several practice rounds together. Model strategies students can use to make the calculations, then invite student volunteers to take a turn.
  4. Pair students up and allow them to play the game together for 10-15 minutes.
  5. Bring the class back to a whole-group discussion and talk about the game play strategies they used. Ask questions such as: Was it smarter to focus on making your own number or to focus on blocking Okta's next move? Were there any cards which were almost always a good number to pick? Any that were usually a bad number to pick? Did the concepts of even and odd come into play? If so, how? How was understanding the associative property useful during game play? How did rounding strategies apply? How would the inclusion of a '0' card have changed the game? If you could change one element of the game to make it easier to play, what would you change? You may want to also have students reflect in writing as an assessment or for homework.
  6. Allow students more time to explore the game on their own or with a partner, either in school or at home.
  7. Challenge students to use standard playing cards or other numbered cards to create their own rules for a Deep Sea Duel-inspired game. They may wish to create combinations that add up to a number other than 9 or 16, or restructure the Deep Sea Duel game entirely. Encourage students to think of creative ways to practice and apply their math skills!

Extension Activities:

More games by this developer are available on the Illuminations website.
Be sure to check out the other Math Games featured in GameUp!

BrainPOP Movies:

Associative Property
Adding and Subtracting Integers (Activity Page Answer Key)
Estimating (Activity Page Answer Key)
Rounding (Activity Page Answer Key)