Lesson Plan: Two-Digit by Two-Digit Addition
Grade Level: Grade 1
Subject: Math
Duration: 50 minutes

 

1. Learning Objectives

By the end of this lesson, students will be able to:

• Represent and solve two-digit plus two-digit addition problems within 100 using place-value models (base-ten blocks) and drawings.
• Explain the steps of adding tens and ones, including making a ten when necessary.

2. Standards Alignment

• CCSS.MATH.CONTENT.1.NBT.C.4 Add within 100, including adding a two‐digit number and a two‐digit number, using concrete models or drawings and strategies based on place value.
• CCSS.MATH.CONTENT.1.NBT.C.5 Given a two‐digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

3. Materials & Resources

• Sets of base‐ten blocks (tens rods and one‐unit cubes), one per student pair
• Place‐value mats labeled “Tens” and “Ones”
• Whiteboard & markers
• Individual whiteboards and dry‐erase markers for students
• 2‐digit addition worksheet (5 problems)
• Exit tickets (1 problem each)
• Chart paper with example problem
• Visual number line (0-100)
• Sentence frames for ELLs (e.g., “____ tens + ____ tens = ____ tens.”)

4. Instructional Activities & Teaching Strategies

1. Hook / Number Talk (5 minutes)

• Display two numbers (e.g., 23 and 15) on the board.
• Ask: “How many tens? How many? What strategies might help us add these quickly?”
• Listen for responses like “Group the ones first,” “Make a ten,” or “Count on.”

1. Direct Instruction (10 minutes)

• Model with base‐ten blocks on chart paper: – Place 23 (2 rods, 3 cubes) on the mat. – Place 15 (1 rod, 5 cubes) beside it.
• Demonstrate combining ones: 3 cubes + 5 cubes = 8 cubes.
• Combine tens rods: 2 rods + 1 rod = 3 rods.
• Show final sum: 38.
• Repeat with a “making a ten” example (e.g., 27 + 18), highlighting regrouping of 10 ones into 1 ten rod.

1. Guided Practice (15 minutes)

• Pair students; give each pair base‐ten blocks + place‐value mat.
• Project Problem #1 on the whiteboard (e.g., 34 + 22).
• Students model together, teacher circulates, prompts: – “How many ones?” – “Do we need to make a ten?” – “What is our total?”
• Discuss whole‐class responses, using sentence frames for scaffolding.
• Repeat with Problems #2 and #3, gradually releasing responsibility to students.

1. Independent Practice (15 minutes)

• Distribute individual whiteboards and worksheet (Problems #4-#5).
• Students solve two 2-digit addition problems using either: – Base‐ten blocks (if needed) – Drawing tens/ones – Mental strategy (for early finishers)
• Teacher circulates, offers support, and notes misconceptions.

1. Closure & Exit Ticket (5 minutes)

• Ask a volunteer to demonstrate one problem at the board.
• Distribute exit ticket: a single two‐digit addition problem (e.g., 46 + 29).
• Collect tickets for quick formative assessment.

5. Assessment Methods

• Formative: Observation during guided/independent practice, anecdotal notes, whiteboard checks
• Exit Ticket: Single problem to verify individual understanding
• Student Explanations: Use sentence frames to assess verbal explanation of steps

6. Differentiation Strategies

• 
  Struggling Learners – Continue use of manipulatives; work in a 3-student support group – Provide number-line visuals and one-on-one mini-lessons – Offer partially completed place‐value mats
• 
  English Language Learners – Provide sentence frames and word banks (e.g., “ones,” “tens,” “total”) – Use pair-share so they can rehearse language – Label manipulatives in students’ home languages if possible
• 
  Advanced Learners – Challenge with word problems requiring two-digit addition (e.g., “If Sara has 47 stickers and she buys 36 more, how many does she have?”) – Introduce adding three two‐digit numbers or mental adding of 10 more/less (standard 1.NBT.C.5)

7. Lesson Timeline

Time	Component	Activity
0-5 min	Hook / Number Talk	Pose 23 + 15; elicit strategies
5-15 min	Direct Instruction	Model with base‐ten blocks; demonstrate regrouping
15-30 min	Guided Practice	Pairs solve 3 problems with teacher support
30-45 min	Independent Practice	Students complete 2 problems on whiteboards/worksheet
45-50 min	Closure & Exit Ticket	Volunteer demo; exit ticket collection

This 50-minute lesson uses hands‐on modeling, guided practice, and formative assessments to ensure that first graders master two-digit by two-digit addition in alignment with Common Core standards.