Addition Intervention Teacher Guide Tier 2 Intervention • Grade 2 • Week 1
Addition Strategies Guide
Standard: CCSS 2.NBT.B.5
Intervention Framework (25 Min Daily)
Warm-Up (5 min) Subitizing, ten-partners, counting tens
Model (7 min) I Do: Think-aloud using base-ten & equations
Guided (8 min) We Do: Paired discourse with workspace steps
Quick Check (5 min) You Do: Independent entry & rubric tally
Day 1: Make a Ten Strategy
Focus: 2-Digit + 1-Digit
Objective: Students will decompose a single-digit addend to make the nearest ten before adding the remainder (e.g., 28 + 6 = 28 + 2 + 4 = 30 + 4 = 34).
Teacher Model Script: “Look at 37 + 5. How many more does 37 need to reach the next friendly ten, 40? It needs 3! Let us break 5 into 3 and 2. 37 plus 3 is 40. Now add the leftover 2: 40 + 2 = 42.”
Scaffold: Have students circle the pair that forms the landmark ten.
Check for Understanding: Can the student explain why breaking 5 into 3 and 2 is helpful?
Day 2: Partial Sums (Break Apart by Tens & Ones)
Focus: 2-Digit + 2-Digit
Objective: Students will decompose both addends into tens and ones, add tens together, add ones together, and combine the totals (e.g., 34 + 25 = 30 + 20 + 4 + 5 = 50 + 9 = 59).
Teacher Model Script: “In 43 + 38, break 43 into 40 + 3 and 38 into 30 + 8. Combine the tens: 40 + 30 = 70. Combine the ones: 3 + 8 = 11. Now combine 70 + 11 to get 81.”
Scaffold: Write tens in one column and ones in an adjacent column to prevent place value mixing.
Check for Understanding: Verify student correctly groups 40 + 30 rather than treating 4 and 3 as single digits.
Grade 2 Math Intervention • Addition Strategies Page 1 of 3
Tier 2 Intervention • Grade 2 • Week 1
Daily Plans: Days 3 & 4
Standard: CCSS 2.NBT.B.5
Day 3: Changing Addend Order and Grouping
Focus: Commutative & Associative
Objective: Students will rearrange and group addends to make friendly combinations of ten when adding three numbers (e.g., 17 + 25 + 13 = (17 + 13) + 25 = 30 + 25 = 55).
Teacher Model Script: “Look at 16 + 28 + 14. Which ones digits combine to make a ten? 6 and 4 make 10! Let us group 16 and 14 first. 16 + 14 = 30. Now we add 28: 30 + 28 = 58. Changing the order made it much easier!”
Key Vocabulary: Commutative property (order does not change sum), friendly ten combinations.
Scaffold: Have students draw connecting lines between addends whose ones digits add up to 10.
Common Misconception: Students adding strictly left-to-right without scanning for tens combinations.
Day 4: Place Value Jumps (Jump by Tens, Then Ones)
Focus: Mental & Workspace Decomposition
Objective: Students will keep the first addend whole and add the second addend by decomposed tens then ones (e.g., 47 + 36 = 47 + 30 = 77; 77 + 3 = 80; 80 + 3 = 83).
Teacher Model Script: “Start at 47. Decompose 36 into 3 tens and 6 ones (30 and 6). Take big jumps of ten: 47 + 10 = 57, 57 + 10 = 67, 67 + 10 = 77. Now add 6: jump 3 to reach 80, and 3 more to reach 83!”
Scaffold: Provide step-by-step recording lines: Step 1 (Add tens), Step 2 (Reach next landmark), Step 3 (Add remaining ones).
Target Feedback: If a student miscounts tens, have them touch fingers representing groups of 10.
Weekly Strategy Summary Matrix
Strategy
Example
Best Used When
Make a Ten
28 + 6 = 28 + 2 + 4 = 34
One addend ends in 7, 8, or 9
Partial Sums
(40 + 20) + (5 + 3) = 68
Adding two double-digit numbers
Order & Grouping
(14 + 16) + 25 = 30 + 25 = 55
Adding three numbers with ten-partners
Grade 2 Math Intervention • Addition Strategies Page 2 of 3
Tier 2 Intervention • Grade 2 • Week 1
Day 5 Plan & Progress Check
Standard: CCSS 2.NBT.B.5
Day 5: Strategy Showcase & Weekly Progress Check
Review & Assess
Objective: Students will select and execute an efficient place-value strategy to solve 2-digit addition problems within 100 and justify their method.
Warm-Up (5 min): Flashcard game — students name the fastest strategy for displayed cards (e.g., for 58 + 7: “Make a ten!”; for 44 + 32: “Tens and ones!”).
Guided Showcase (8 min): Compare two student work samples solving 36 + 27. Celebrate diverse valid strategies (partial sums vs make a ten).
Independent Progress Check (12 min): Administer Week 1 Check (Worksheet Day 5). Observe independently without coaching.
Week 1 Progress Monitoring Rubric
Level
Descriptor (Place Value & Properties)
Instructional Action
3 • Proficient
Accurately uses place value decomposition or make-ten strategy; clear written work showing tens and ones.
Advance to Week 2 subtraction strategies; offer three-addend extensions.
2 • Developing
Decomposes tens and ones correctly but makes minor arithmetic slips when recombining totals.
Provide quick warm-up on combining two-digit tens with single-digit ones.
1 • Novice
Counts on by ones; mixes up tens and ones values (e.g., adds 30 + 4 as 3 + 4 = 7).
Provide concrete base-ten block pairing alongside written steps during Week 2.
Diagnostic Observational Prompts
Does the student identify digits by their place value (e.g., saying “forty” instead of “four”)?
When regrouping 10 ones into 1 ten, does the student record the new ten accurately in their total?
Can the student choose between “Make a Ten” and “Partial Sums” based on the specific addends?
Grade 2 Math Intervention • Addition Strategies Page 3 of 3
Addition Strategies Student Worksheets Math Intervention • Week 1
Day 1: Make a Ten to Add
Name: Date:
Strategy: Break apart the smaller number to make a friendly ten with the larger number. Add the leftover ones.
Problem 1 28 + 6 = ______
Show your work below. How did you break apart 6 to make 30?
Problem 2 47 + 5 = ______
Show your work below. How did you break apart 5 to make 50?
Problem 3 69 + 8 = ______
Show your work below. How did you break apart 8 to make 70?
Problem 4 56 + 7 = ______
Show your work below. How did you break apart 7 to make 60?
Grade 2 Math Intervention • Fluency Within 100 Worksheet 1
Math Intervention • Week 1
Day 2: Break Apart by Place Value
Name: Date:
Strategy: Break both numbers into tens and ones. Add the tens together, add the ones together, then add the two totals.
Problem 1 34 + 25 = ______
Break into tens and ones. Show all steps below.
Problem 2 52 + 36 = ______
Break into tens and ones. Show all steps below.
Problem 3 45 + 38 = ______
Add tens, then add ones. Remember to compose a ten if needed.
Problem 4 27 + 64 = ______
Add tens, then add ones. Remember to compose a ten if needed.
Grade 2 Math Intervention • Fluency Within 100 Worksheet 2
Math Intervention • Week 1
Day 3: Change Addend Order and Grouping
Name: Date:
Strategy: Look for numbers with ones digits that make 10. Group those two numbers first, then add the remaining number.
Problem 1 18 + 25 + 12 = ______
Circle the two numbers that make an easy ten. Show your steps below.
Problem 2 34 + 19 + 16 = ______
Circle the two numbers that make an easy ten. Show your steps below.
Problem 3 23 + 45 + 17 = ______
Group friendly pairs first, then add. Show your steps below.
Problem 4 15 + 38 + 25 = ______
Group friendly pairs first, then add. Show your steps below.
Grade 2 Math Intervention • Fluency Within 100 Worksheet 3
Math Intervention • Week 1
Day 4: Add Tens First, Then Ones
Name: Date:
Strategy: Keep the first number whole. Break the second number into tens and ones. Add the tens first, then add the ones.
Problem 1 36 + 28 = ______
Add 20 first: 36 + 20 = ______. Then add 8. Show work below.
Problem 2 45 + 37 = ______
Add 30 first: 45 + 30 = ______. Then add 7. Show work below.
Problem 3 58 + 26 = ______
Add tens first, then add ones. Show all steps below.
Problem 4 29 + 44 = ______
Add tens first, then add ones. Show all steps below.
Grade 2 Math Intervention • Fluency Within 100 Worksheet 4
Math Intervention • Week 1 Check
Day 5: Addition Fluency Check
Name: Date:
Directions: Solve each problem using your best strategy (Make a Ten, Tens & Ones, or Addend Order). Show your thinking clearly in each box.
Problem 1 48 + 7 = ______
Show your strategy in the space below.
Problem 2 35 + 42 = ______
Show your strategy in the space below.
Problem 3 56 + 28 = ______
Show your strategy in the space below.
Problem 4 19 + 34 + 21 = ______
Show your strategy in the space below.
Grade 2 Math Intervention • Fluency Within 100 Worksheet 5 • Score: ___ / 4
Subtraction Intervention Teacher Guide Tier 2 Intervention • Grade 2 • Week 2
Subtraction Strategies Guide
Standard: CCSS 2.NBT.B.5
Week 2 Instructional Architecture
Days 6–7: Place Value Subtract tens then ones; decompose a ten into 10 ones when necessary.
Days 8–9: Inverse Logic Use “Think Addition” to find difference; verify subtraction answers using addition.
Day 10: Mastery Review Comprehensive 2-week fluency assessment and diagnostic placement check.
Day 6: Subtract Tens Then Ones (No Regrouping)
Focus: Mental Place Value
Objective: Students will decompose the subtrahend into tens and ones, subtract the tens from the minuend, and then subtract the ones (e.g., 68 - 25 = 68 - 20 = 48; 48 - 5 = 43).
Teacher Model Script: “To solve 57 - 23, decompose 23 into 20 and 3. Start at 57. Subtract the 2 tens first: 57 - 20 = 37. Now subtract the 3 ones: 37 - 3 = 34. Subtracting tens first makes the problem simple!”
Scaffold: Have students record the intermediate number clearly before subtracting the ones.
Check for Understanding: Ensure the student subtracts tens from the tens place rather than changing the ones digit.
Day 7: Decomposing a Ten (With Regrouping)
Focus: Regrouping Concepts
Objective: Students will rename one ten as 10 ones when the minuend has fewer ones than the subtrahend (e.g., 52 - 27: rewrite 52 as 4 tens and 12 ones, or subtract 20 to get 32, then subtract 2 and 5).
Teacher Model Script: “Look at 63 - 28. Can we subtract 8 ones from 3 ones? No! We must unbundle 1 ten from 60. Now we have 5 tens and 13 ones. 13 minus 8 is 5. 50 minus 20 is 30. Our answer is 35.”
Common Misconception: “Smaller from larger” error — subtracting 8 - 3 = 5 instead of decomposing a ten. Intervene immediately by asking: “How many ones did we start with?”
Check for Understanding: Does the student recognize when decomposing a ten is required?
Grade 2 Math Intervention • Subtraction Strategies Page 1 of 3
Tier 2 Intervention • Grade 2 • Week 2
Daily Plans: Days 8 & 9
Standard: CCSS 2.NBT.B.5
Day 8: Think Addition to Subtract (Count Up Strategy)
Focus: Distance & Landmarks
Objective: Students will rewrite a subtraction problem as an unknown-addend equation and count up to find the difference (e.g., 72 - 47 = ___ becomes 47 + ___ = 72; jump 3 to 50, jump 20 to 70, jump 2 to 72 = 25).
Teacher Model Script: “Subtraction finds the distance between two numbers. Instead of counting backwards, start at 47 and jump up to 72! First jump to the next friendly ten: 47 + 3 = 50. Jump tens: 50 + 20 = 70. Jump to 72: 70 + 2 = 72. Add the jumps: 3 + 20 + 2 = 25!”
Key Benefit: Eliminates regrouping errors for students who struggle with unbundling.
Check for Understanding: Can the student correctly sum their jump distances (3 + 20 + 2)?
Day 9: Fact Power & Inverse Checks
Focus: Operation Relationship
Objective: Students will demonstrate the inverse relationship between addition and subtraction by checking subtraction solutions using addition (e.g., solve 84 - 36 = 48, then verify: 48 + 36 = 84).
Teacher Model Script: “Addition and subtraction are opposites. If 84 - 36 = 48, then putting our parts back together must equal our starting whole: 48 + 36 = 84. If the check does not match 84, we know we need to re-examine our work.”
Scaffold: Provide a two-box format: “Solve Subtraction” on the left, “Addition Check” on the right.
Common Misconception: Writing the check numbers mechanically without actually performing the addition to verify equality.
Strategy Selection Guide for Subtraction
Strategy
When to Use
Key Student Move
Subtract Tens Then Ones
No regrouping required (e.g., 76 - 32)
76 - 30 = 46 → 46 - 2 = 44
Think Addition (Count Up)
Numbers are close or subtrahend ends in 7, 8, 9
Jump from subtrahend to next ten, then to whole
Decompose a Ten
Ones digit of subtrahend is greater
Rename 1 ten as 10 ones before subtracting
Grade 2 Math Intervention • Subtraction Strategies Page 2 of 3
Tier 2 Intervention • Grade 2 • Week 2
Day 10 Plan & Unit Mastery
Standard: CCSS 2.NBT.B.5
Day 10: Unit Mastery Check & Strategy Reflection
Summative Review
Objective: Students will fluently add and subtract within 100 using self-selected efficient strategies based on place value, properties, and inverse relationships.
Warm-Up (5 min): Fact family speed rally — given numbers (e.g., 35, 45, 80), students name all four related addition and subtraction facts.
Strategy Readiness (5 min): Remind students they have a toolbox: Make a Ten, Decompose Tens and Ones, Count Up, and Addition Check.
Independent Unit Assessment (15 min): Administer Day 10 Worksheet. Evaluate both accuracy and strategy execution.
Unit Fluency Mastery Rubric (2.NBT.B.5)
Performance
Criteria (Accuracy & Strategy)
Next Instructional Step
Mastery (4/4)
Accurately solves addition and subtraction problems; articulates place value strategies clearly; verifies work.
Exit Tier 2 intervention; provide 3-digit place value extension (2.NBT.B.7).
Approaching (3/4)
Accurate with addition; occasional computational error when decomposing a ten in subtraction.
Continue 10-minute daily warm-up targeting “Think Addition” counting up.
Needs Support (≤2/4)
Relies heavily on fingers or tallies; persistent place value confusion (tens vs. ones).
Intensify intervention with concrete base-ten manipulatives and ten-frames.
Post-Intervention Progress Documentation
Addition Fluency Rate: Accurate within 100 using decomposition / properties: [ ] Yes [ ] Emerging
Subtraction Fluency Rate: Accurate within 100 using place value / inverse: [ ] Yes [ ] Emerging
Grade 2 Math Intervention • Subtraction Strategies Page 3 of 3
Subtraction Strategies Student Worksheets Math Intervention • Week 2
Day 6: Subtract Tens Then Ones
Name: Date:
Strategy: Break the second number into tens and ones. Subtract the tens first from the starting number, then subtract the ones.
Problem 1 58 - 24 = ______
Subtract 20 first: 58 - 20 = ______. Then subtract 4. Show steps below.
Problem 2 76 - 32 = ______
Subtract 30 first: 76 - 30 = ______. Then subtract 2. Show steps below.
Problem 3 89 - 45 = ______
Subtract tens first, then subtract ones. Show your steps below.
Problem 4 67 - 35 = ______
Subtract tens first, then subtract ones. Show your steps below.
Grade 2 Math Intervention • Fluency Within 100 Worksheet 6
Math Intervention • Week 2
Day 7: Decompose a Ten to Subtract
Name: Date:
Strategy: When there are not enough ones to subtract, unbundle 1 ten into 10 ones. Then subtract the ones and the tens.
Problem 1 52 - 27 = ______
Unbundle 1 ten: 52 becomes 4 tens and 12 ones. Show work below.
Problem 2 63 - 38 = ______
Unbundle 1 ten: 63 becomes 5 tens and 13 ones. Show work below.
Problem 3 71 - 45 = ______
Decompose a ten to get more ones. Show all steps below.
Problem 4 84 - 39 = ______
Decompose a ten to get more ones. Show all steps below.
Grade 2 Math Intervention • Fluency Within 100 Worksheet 7
Math Intervention • Week 2
Day 8: Think Addition to Subtract
Name: Date:
Strategy: Turn subtraction into an addition problem! Start at the smaller number and count up to friendly tens to find the total distance.
Problem 1 62 - 48 = ______
Think: 48 + ______ = 62. Count up to 50, then to 62. Show jumps below.
Problem 2 71 - 36 = ______
Think: 36 + ______ = 71. Count up to 40, then to 71. Show jumps below.
Problem 3 83 - 57 = ______
Think: 57 + ______ = 83. Count up to friendly numbers. Show work below.
Problem 4 90 - 44 = ______
Think: 44 + ______ = 90. Count up to friendly numbers. Show work below.
Grade 2 Math Intervention • Fluency Within 100 Worksheet 8
Math Intervention • Week 2
Day 9: Check Subtraction with Addition
Name: Date:
Strategy: Addition and subtraction undo each other! First solve the subtraction. Then add your answer to the smaller number to verify you get the starting number.
Problem 1 64 - 28 = ______
Solve on the left, then check with addition on the right.
Solve:
Addition Check:
Problem 2 75 - 39 = ______
Solve on the left, then check with addition on the right.
Solve:
Addition Check:
Problem 3 82 - 46 = ______
Solve on the left, then check with addition on the right.
Solve:
Addition Check:
Problem 4 91 - 53 = ______
Solve on the left, then check with addition on the right.
Solve:
Addition Check:
Grade 2 Math Intervention • Fluency Within 100 Worksheet 9
Math Intervention • Unit Mastery Check
Day 10: Addition & Subtraction Fluency
Name: Date:
Directions: Solve each problem using an efficient place value or operation strategy. Show your work clearly in each workspace.
Problem 1 (Addition) 57 + 36 = ______
Show your place value addition strategy below.
Problem 2 (Subtraction) 81 - 48 = ______
Show your subtraction strategy below.
Problem 3 (Three Addends) 28 + 19 + 32 = ______
Group friendly tens first, then add. Show work below.
Problem 4 (Solve & Check) 74 - 29 = ______
Solve the subtraction, then check with addition below.
Grade 2 Math Intervention • Fluency Within 100 Worksheet 10 • Score: ___ / 4
