• Groups of 2
• Give students access to base-ten blocks.

• “Diego and Elena drew base-ten diagrams to find the value of .”
• “Think about what is the same or different on your own. Then discuss your ideas with your partner.”
• 1 minute: quiet think time
• 2–3 minutes: partner discussion

MLR2 Collect and Display

• Circulate, listen for, and collect the language students use to describe the diagrams and how the ten is decomposed. Listen for “break apart a ten,” “decompose,” “tens,” and “need more ones.”
• Record students’ words and phrases on a visual display and update it throughout the lesson.
• Share responses. Consider asking:
  • “Did Diego and Elena find the same value for ? How do you know?”
  • “What is the difference between their diagrams?”  
• “Tyler found the value by using equations. Diego says Tyler’s equations match his diagram. Elena says the equations match her diagram. Who do you agree with?”
• 2 minutes: independent work time
• 4 minutes: partner discussion
• Monitor for students who agree with Diego, Elena, or both and can explain their reasoning with connections to the diagrams.

• Groups of 2
• Give each student a copy of the recording sheet and a set of the number cards.
• Demonstrate removing the cards that show 0 and 10 and setting them aside.
• “We are going to learn a new way to play Target Numbers. You and your partner will start with 99 and race to see who can get closest to 0.”
• “First, represent 99 with base-ten blocks. When it’s your turn, draw a card. Decide whether you want to subtract that many tens or that many ones. Then show the subtraction with your blocks and write an equation on your recording sheet.”
• “Take turns drawing a card and subtracting until you play 6 rounds or one player reaches 0. After 6 rounds, whoever is closest to 0 is the winner.”
• As needed, demonstrate a round with a student volunteer.

• 10–15 minutes: partner work
• Monitor for examples when students pick cards that require them to decompose a ten to subtract by place.