Thank you for your interest in NCTM’s Illuminations. Beginning in mid-April, all Illuminations content will be moving to nctm.org/illuminations. Interactives will remain openly available and NCTM members will have access to all Illuminations lessons with new filtering and search options. We hope you will continue to utilize and enjoy these resources on nctm.org.

## Deep Sea Duel

3-5, 6-8
Standards:
Math Content:
Number and Operations, Algebra

Okta challenges you to a duel! That crazy octopus wants to play you in a game where 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.

This interactive is also optimized for your desktop and tablet.

### Object of the Game

In the 9-bubble game, the object is to choose numbers so that the sum of any three of them is equal to the specified sum.

In the 16-bubble game, the object is to choose numbers so that the sum of any four of them is equal to the specified sum.

### Settings

• Number of Players: Play against Okta or a friend.
• Number of Bubbles: Choose either 9 or 16 bubbles.
• Complexity: Negative numbers and/or decimals are an option to increase the difficulty of the game.
• Language: Choose between English or Spanish.

### During the Game

• During the game, you and your opponent will take turns selecting cards. The first one to get the specified sum with three cards (in the 9‑card game) or four cards (in the 16‑card game) wins the game. The sum to be obtained will be shown on the seashell in the top center of the game.
• A running total of the number of wins will be kept. Ties are not recorded.
• The Help clam can be used to see these object of the game. The Settings button will allow you to change the type of game you want to play.