# Lesson 11

Division Game Day

## Warm-up: Number Talk: Divide 48 (10 minutes)

### Narrative

The purpose of this Number Talk is to elicit strategies and understandings students have for finding related quotients, which will be helpful later in this lesson when students divide within 100.

When students use the relationship between multiplication and division and known division facts to find a division fact they don’t know, they look for and make use of structure (MP7).

### Launch

• Display one expression.
• “Give me a signal when you have an answer and can explain how you got it.”
• 1 minute: quiet think time

### Activity

• Keep expressions and work displayed.
• Repeat with each expression.

### Student Facing

Find the value of each expression mentally.

• $$48\div2$$
• $$48\div3$$
• $$48\div4$$
• $$48\div6$$

### Activity Synthesis

• “There are lots of ways to divide 48. What are some other numbers that can be divided in many ways?” (24, because it can divided by 2 to get 12 or by 4 to get 6. 100, because it can be divided by 2, 4, 5, 10, 20, or 25.)

## Activity 1: Play Race to 1 (15 minutes)

### Narrative

The purpose of this activity is for students to practice division within 100 by playing a game called Race to 1. The goal of the game is to repeatedly divide numbers until they reach one.

Engagement: Develop Effort and Persistence. Check in and provide each group with feedback that encourages collaboration and community.
Supports accessibility for: Social-Emotional Functioning, Organization

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• “Take a minute to read the directions for Race to 1.”
• 1 minute: quiet think time
• “Let’s look at a sample game. Jada rolled a 3 on her first turn, then rolled 2 a few times afterwards. Talk with your partner about what her next move should be if she rolls 2 on her next turn.” (She should divide 4 or 6 by 2 because those moves get her really close to one.)
• 1 minute: partner discussion
• Share responses.
• Give each group a number cube.

### Activity

• “Play Race to 1 with your partner.”
• 10–15 minutes: partner work time
• If students finish early, have them play again. Students can fill in the same numbers from the first game at the top of the columns of the second game or use the numbers 24, 36, 48, and 72 for a challenge.

### Student Facing

Directions for Race to 1

1. Roll a number cube. The number you roll is your divisor. (If you roll a 5, roll again.)
2. Choose one number from the top row of your table. Divide it by your divisor.
3. Write a division expression and record the quotient in the table. Your turn is done.

1. Roll a number cube. The number you roll is your divisor. (If you roll a 5, roll again.)
2. Choose either a quotient from one of your past turns or a new number from the top row of the table. Divide it by your divisor.
3. Write a division expression and record the quotient in the table.
4. The first player to get a quotient of 1 wins.

Sample Game

Jada rolled 3 on her first turn, then rolled 2 a few times afterwards.

start number

12 16 18 24
division expression $$12\div3$$ $$16\div2$$ $$24\div2$$
quotient 4 8 12
division expression $$12\div2$$
quotient 6
division expression
quotient

Game 1

start number

12 16 18 24
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient

Game 2

start number

division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient
division expression
quotient

### Activity Synthesis

• “How was having an efficient way to divide helpful as you played Race to 1?” (I had to decide which number I was going to divide, so it was helpful to be able to do it quickly. I had to divide a few times on each turn.)
• “What was a helpful strategy as you played Race to 1?” (I had to think about which number I could divide by the number I rolled. I divided the smallest number by the largest divisor to try to get to the quotient to be as small as possible so I could get to 1 first.)

## Activity 2: Play Compare, Division (20 minutes)

### Narrative

The purpose of this activity is for students to practice dividing within 100. They do this by revisiting the Compare center introduced in a previous unit. (As was the case then, exclude cards with two-digit divisors from this activity.)

Students may compare expressions by finding the value of each or by reasoning based on the expressions (MP7). (For example, when comparing $$92\div4$$ and $$84\div4$$, they can recognize that $$92\div4$$ is greater because it would be more groups of 4.) When students divide within 100, students should have an efficient method for finding the quotient, but do not need to know the quotient from memory.

MLR8 Discussion Supports. Synthesis: Provide students with the opportunity to rehearse what they will say with a partner before they share with the whole class.

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from:
• Compare, Stage 4

### Launch

• Groups of 2
• Give each group of 2 students a set of pre-cut cards.
• Play a round of Compare against the class.

### Activity

• “Play Compare with your partner.”
• 10-12 minutes: partner work time

### Student Facing

Play Compare with 2 players.

1. Split the deck between the players.
2. Each player turns over a card.
3. Compare the values. The player with the greater value keeps both cards.
4. Play until you run out of cards. The player with the most cards at the end of the game wins.

### Activity Synthesis

• “What were some division strategies that were helpful as you played your game?” (I used multiplication to help me divide. I used quotients that I knew to find quotients that I didn’t know.)

## Lesson Synthesis

### Lesson Synthesis

“Today, we played some division games to practice dividing within 100.”

“How have you made progress in your division fluency this year?” (I use multiplication to divide because multiplication and division are related. I got better at using a quotient I know to figure out a quotient I don’t know. I learned to divide large numbers in parts to make it easier. I’m a lot faster at dividing than when I first learned about it earlier in the year.)