Add two 2-digit numbers, no regrouping

Teaching Notes

Focus on place value understanding, emphasizing adding ones to ones and tens to tens separately. Use manipulatives like base-ten blocks to model the process, ensuring no trades are needed.

Vocabulary

Place value: The value of a digit based on its position.

Regrouping: Exchanging tens for ones or vice versa.

Common Mistakes

• Adding ones and tens incorrectly (e.g., 23+45 -> 60+8).
• Misaligning place values when writing vertically.
• Attempting to regroup when it's not needed.

Differentiation

Discussion Questions

• How is adding 2-digit numbers different from adding 1-digit numbers?
• Why is it important to keep the ones and tens separate when we add?
• Can you think of a real-life situation where you would need to add two 2-digit numbers without regrouping?

Extension Activities

• Use a place value chart.
• Draw base-ten blocks.
• Estimate the sum first.

Parent Tip

Use coins (dimes and pennies) to model addition.

Skill Cluster

Addition & Place Value

Estimated Time

15 minutes

Skills Practiced

Prerequisites

• Add 1-digit numbers (within 20)
• Place value (tens and ones)
• Count by tens and ones

Next Steps

• Add two 2-digit numbers with regrouping
• Add three 2-digit numbers
• Subtract 2-digit numbers (no regrouping)