# Multiplication Using the Distributive Property Lesson Plan: Mt. Multiplis

This lesson plan, adaptable for grades 3-5, features the demo version of the multiplication game, Mt. Multiplis from our partner, Teachley. This interactive game uses visual models that encourage students to think about and solve problems in different ways using the properties of multiplication, particularly the distributive property. All Teachley games are developed and supported by cognitive science research.

### Students will:

- Use effective math strategies based on mathematical properties to solve multiplication problems.
- Express their mathematical thinking using the SnapThought® tool.

### Materials:

- Computers or other devices with Internet access
- Interactive whiteboard

### Preparation:

This lesson features a multiplication game developed by teachers and researchers at Teachley, an educational technology company. The game teaches effective multiplication strategies and guides students to apply the distributive property to solve problems.Preview and play Mt. Multiplis to plan how you will adapt it to your students’ needs.

For ideas on how to use SnapThought with this game, read Mt. Multiplis: SnapThought Prompts for more information and specific SnapThought prompts to provide students during game play.

Depending on your classroom routines and available technology, you may want to consider these grouping options:

- 1:1 with students and devices
- Two to three students sharing one device and swapping ideas and the device back and forth
- Station model where small groups rotate through using the devices

- The demo version that this lesson is based on includes two levels of the game.
- The first level features 5-factor problems, utilizing groups of 5.
- The second level features 4-factor problems with 4 groups of x. At this level, the game encourages students to think in terms of 2 groups of x and then double it.

You might choose to build background knowledge or reinforce topics with these BrainPOP movies: Multiplication, Commutative Property, Distributive Property.

### Lesson Procedure:

- Play one of the recommended BrainPOP movies suggested in Preparation to build background or to make connections to prior knowledge.
- Write a simple 5-factor multiplication problem on the board, such as, “3 x 5 = _” and ask students to share how they would solve this problem. Although some may have just memorized the fact, encourage others to describe how they might solve it if they didn’t know the answer. Provide manipulatives and/or pencil and paper for students to show their strategies. After students share their ideas, model how to think think strategically about the problem by showing how 3 x 5 is the same as 2 groups of 5 plus 1 more group of 5 (10 + 5).
- Repeat step 2 but with a 4-factor problem, such as 4 x 6. Again, ask students to share how they solve the problem if they haven’t memorized the fact. Using the example from step 2, they might solve it by thinking of two groups of 6 plus another two groups (12 + 6 + 6). After students share their ideas, be sure to model the doubling strategy by showing how to double 2 groups of 6 (12 doubled) to get the answer 24.
- Project Mt. Multiplis for the class to see. Demonstrate or invite students to figure out how to play:
Click the bridge to plan it, and then again to build it.
Drag the factor cards on the left onto the bridge area. The total is additive.
Once you build a bridge, cross it by clicking the island you want to go to.
Demonstrate how they can undo the last move by clicking the Undo button on the right. Or they can clear the whole bridge by clicking Reset.
Project Mt. Multiplis for the class to see. Demonstrate or invite students to figure out how to play:
- Click the bridge to plan it, and then again to build it.
- Drag the factor cards on the left onto the bridge area. The total is additive.
- Once you build a bridge, cross it by clicking the island you want to go to.
- Demonstrate how they can undo the last move by clicking the Undo button on the right. Or they can clear the whole bridge by clicking Reset.
- On Level 2, demonstrate how to use the Double It! button on the left side to double the planks to come up with the answer.

- Depending on your students’ needs, you can play several rounds of the game as a whole class, inviting volunteers to come up and try the different strategies.
- Now have students explore the game independently or in pairs, Allow 10-15 minutes for game play.
- If students have individual logins through My BrainPOP, encourage them to use the SnapThought® tool to take snapshots during game play, and reflect on their strategies. See Mt. Multiplis: SnapThought Prompts for suggested prompts.
- Circulate the room as students play, listening as they use or discuss their strategies, and provide help as needed.
- Bring students back to a whole class discussion and have volunteers share their strategies for game play. Ask if they used any strategies that were new for them. Ask what they liked about the strategies they used and what they didn’t like.
- Encourage students to revisit Mt. Multiplis throughout the school year to practice multiplication strategies. NOTE: The full version of the game is available at teachley.com.