Error Detective Activity Error Detective Activity
Targeted Review • Catch the Regrouping Clues
Skill Lab • Week 1
Detective Name:
Date:
Cases Solved:
/ 4
Each math case below contains a classic regrouping mistake . Circle where the student went wrong, explain the error, and calculate the correct solution.
Case #1: Mystery of the Inverted Digits Subtraction
Flawed Student Work
62
− 38
36
Your Correction
Correct: _____
What went wrong?
Case #2: The Disappearing Ten Addition
Flawed Student Work
367
542
Your Correction
Correct: _____
What went wrong?
Case #3: The Unreduced Column Subtraction
Flawed Student Work
542
− 186
466
Your Correction
Correct: _____
What went wrong?
Case #4: The Shifting Columns Addition
Flawed Student Work
486
1216
Your Correction
Correct: _____
What went wrong?
Independent Practice: Apply the Golden Rules
Show all regrouping trades clearly
Problem A Addition
578
Work: Sum: _____
Problem B Subtraction
714
− 358
Work: Diff: _____
Problem C Subtraction
802
− 436
Work: Diff: _____
Detective Rule: Always check if the top digit has enough before subtracting! Digit Dynamics • Review Lab 1
Regrouping Tracker Sheet 10-Week Regrouping Tracker
Standardized Progress Monitoring Data Sheet
10 Probes × 10 Items
Student:
Teacher:
Grade:
Goal:
≥ 8 / 10 (80%)
10-Week Growth Trajectory (Score Out of 10)
Aim Line (8/10) Student Score
Mastery Aim Line (8/10)
10 pts
8 pts
6 pts
4 pts
2 pts
0 pts
P1 P2 P3 P4 P5 P6 P7 P8 P9 P10
Quantitative Log: 10 Standardized Probes
Log scores immediately after administration
Probe Date Add (/5) Sub (/5) Total (/10) % Accuracy Target Met? Teacher Notes / Error Patterns Probe 1 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________ Probe 2 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________ Probe 3 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________ Probe 4 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________ Probe 5 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________ Probe 6 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________ Probe 7 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________ Probe 8 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________ Probe 9 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________ Probe 10 ___/___ ___ ___ ___ ___% □ Y □ N ___________________________
Decision Rules (MTSS / RTI) Mastery Criterion: 3 Consecutive Probes ≥ 8/10 (80%)
Tier 1 Exit Criterion: 3 consecutive data points at or above the aim line (8+ pts). Transition to monthly maintenance.
Progressing (Continue): Scores showing positive trend line. Continue current tier interventions and weekly probes.
Intervention Change: 4 consecutive data points below aim line. Intensify support or shift pedagogical strategy.
Digit Dynamics • 10-Week Progress Monitoring Portfolio Form PM-10
Progress Probe One Assessment 01
Progress Probe One
Multi-Digit Operations • Form 1
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
58
Work: Ans: ________
2 2-Digit Sub
74
− 38
Work: Ans: ________
3 3-Digit Add
347
Work: Ans: ________
4 3-Digit Sub
526
− 248
Work: Ans: ________
5 3-Digit Add
469
Work: Ans: ________
6 3-Digit Sub
635
− 289
Work: Ans: ________
7 Across Zero
504
− 237
Work: Ans: ________
8 Double Zero
700
− 356
Work: Ans: ________
9 4-Digit Add
2,586
Work: Ans: ________
10 4-Digit Sub
4,213
− 1,678
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 1
Progress Probe Two Assessment 02
Progress Probe Two
Multi-Digit Operations • Form 2
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
47
Work: Ans: ________
2 2-Digit Sub
82
− 45
Work: Ans: ________
3 3-Digit Add
286
Work: Ans: ________
4 3-Digit Sub
615
− 278
Work: Ans: ________
5 3-Digit Add
574
Work: Ans: ________
6 3-Digit Sub
742
− 385
Work: Ans: ________
7 Across Zero
605
− 348
Work: Ans: ________
8 Double Zero
800
− 463
Work: Ans: ________
9 4-Digit Add
3,478
Work: Ans: ________
10 4-Digit Sub
5,124
− 2,789
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 2
Progress Probe Three Assessment 03
Progress Probe Three
Multi-Digit Operations • Form 3
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
69
Work: Ans: ________
2 2-Digit Sub
91
− 56
Work: Ans: ________
3 3-Digit Add
458
Work: Ans: ________
4 3-Digit Sub
734
− 358
Work: Ans: ________
5 3-Digit Add
683
Work: Ans: ________
6 3-Digit Sub
853
− 476
Work: Ans: ________
7 Across Zero
702
− 438
Work: Ans: ________
8 Double Zero
600
− 274
Work: Ans: ________
9 4-Digit Add
4,765
Work: Ans: ________
10 4-Digit Sub
6,341
− 2,875
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 3
Zero Busters Activity Zero Busters Activity
Targeted Skill Review • Regrouping Across Zeros
Skill Lab • Week 2
Student:
Date:
Mission: Break the Zero Trap
The Chain-Trade Rule: How to Decompose Across a Zero
Model: 504 − 268
Step 1: Check the Ones
In \(4 - 8\), 4 is too small! Look to tens to borrow, but the tens place is 0 !
Cannot borrow from 0!
Step 2: Hop to Hundreds
Borrow 1 hundred (5 becomes 4 ). Regroup it as 10 tens (0 becomes 10 ).
5 hundreds → 4 h + 10 t
Step 3: Trade to Ones
Now borrow 1 ten from 10 (10 becomes 9 ). Give 10 to ones (4 becomes 14 ). Subtract!
14 − 8 = 6; 9 − 6 = 3; 4 − 2 = 2
Practice Lab: Cross Out and Show Each Chain Trade
Always slash and rewrite the new digit above
Problem 1: Middle Zero 603 − 285
603
− 285
Difference: ___________
Problem 2: Double Zero 800 − 457
800
− 457
Difference: ___________
Problem 3: Across Multiple Places 1,000 − 382
1,000
− 382
Difference: ___________
Problem 4: 4-Digit Zero Internal 3,045 − 1,678
3,045
− 1,678
Difference: ___________
The Golden Sanity Check: Inverse Addition!
Always verify your answer by adding your Difference + Subtrahend (bottom number) . If it equals the top number, you conquered the zeros!
Diff + Sub = Minuend ✓
Digit Dynamics • Precision Skill Lab 2 Zero Busters Intervention
Progress Probe Four Assessment 04
Progress Probe Four
Multi-Digit Operations • Form 4
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
57
Work: Ans: ________
2 2-Digit Sub
63
− 29
Work: Ans: ________
3 3-Digit Add
376
Work: Ans: ________
4 3-Digit Sub
842
− 365
Work: Ans: ________
5 3-Digit Add
487
Work: Ans: ________
6 3-Digit Sub
921
− 458
Work: Ans: ________
7 Across Zero
804
− 367
Work: Ans: ________
8 Double Zero
900
− 538
Work: Ans: ________
9 4-Digit Add
5,384
Work: Ans: ________
10 4-Digit Sub
7,105
− 3,468
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 4
Progress Probe Five Assessment 05
Progress Probe Five
Multi-Digit Operations • Form 5
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
48
Work: Ans: ________
2 2-Digit Sub
75
− 38
Work: Ans: ________
3 3-Digit Add
295
Work: Ans: ________
4 3-Digit Sub
643
− 286
Work: Ans: ________
5 3-Digit Add
569
Work: Ans: ________
6 3-Digit Sub
814
− 357
Work: Ans: ________
7 Across Zero
602
− 258
Work: Ans: ________
8 Double Zero
700
− 429
Work: Ans: ________
9 4-Digit Add
3,694
Work: Ans: ________
10 4-Digit Sub
5,002
− 2,647
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 5
Progress Probe Six Assessment 06
Progress Probe Six
Multi-Digit Operations • Form 6
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
59
Work: Ans: ________
2 2-Digit Sub
84
− 47
Work: Ans: ________
3 3-Digit Add
367
Work: Ans: ________
4 3-Digit Sub
752
− 386
Work: Ans: ________
5 3-Digit Add
648
Work: Ans: ________
6 3-Digit Sub
935
− 467
Work: Ans: ________
7 Across Zero
803
− 456
Work: Ans: ________
8 Double Zero
500
− 267
Work: Ans: ________
9 4-Digit Add
4,839
Work: Ans: ________
10 4-Digit Sub
6,104
− 3,759
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 6
Progress Probe Seven Assessment 07
Progress Probe Seven
Multi-Digit Operations • Form 7
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
67
Work: Ans: ________
2 2-Digit Sub
73
− 37
Work: Ans: ________
3 3-Digit Add
479
Work: Ans: ________
4 3-Digit Sub
825
− 369
Work: Ans: ________
5 3-Digit Add
586
Work: Ans: ________
6 3-Digit Sub
941
− 578
Work: Ans: ________
7 Across Zero
705
− 268
Work: Ans: ________
8 Multiple Zeros
1,000
− 437
Work: Ans: ________
9 4-Digit Add
5,647
Work: Ans: ________
10 4-Digit Sub
8,024
− 3,568
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 7
Growth Showcase Reflection Growth Showcase Reflection
Student Self-Audit & Operation Mastery Celebration
Milestone Portfolio
Mathematician:
Date:
Sequence: Digit Dynamics
My Growth Trajectory: From Baseline to Mastery
Record your scores across the sequence
Week 1 Baseline
____ / 10
Starting Point
Week 5 Midpoint
____ / 10
Zero Skills Added
Week 10 Benchmark
____ / 10
Full Fluency
Net Growth
+ ____ pts
Accuracy Gained!
Regrouping Superpowers I Have Conquered
Always Check First: I look at the top digit to decide if regrouping is needed before subtracting. Remembering Trades: I write regrouped tens and hundreds clearly above the columns and add them. Chain-Trading Zeros: I can trade across middle zeros and double zeros without getting confused. Inverse Sanity Check: I check my subtraction using addition to prove my calculation is 100% correct.
Mathematician's Reflection
1. The most helpful strategy or habit I learned during this sequence was:
2. When I face a multi-digit subtraction problem with multiple zeros, my step-by-step game plan is:
Official Certificate of Operation Mastery
This credential verifies that the student named above has completed the Digit Dynamics 10-Week Monitoring Sequence and demonstrated proficiency in multi-digit addition and subtraction with regrouping.
Educator Signature
Date Certified
Digit Dynamics • Student Growth Portfolio Sequence Complete
Progress Probe Eight Assessment 08
Progress Probe Eight
Multi-Digit Operations • Form 8
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
56
Work: Ans: ________
2 2-Digit Sub
81
− 46
Work: Ans: ________
3 3-Digit Add
385
Work: Ans: ________
4 3-Digit Sub
732
− 458
Work: Ans: ________
5 3-Digit Add
678
Work: Ans: ________
6 3-Digit Sub
924
− 367
Work: Ans: ________
7 Across Zero
604
− 379
Work: Ans: ________
8 Double Zero
800
− 542
Work: Ans: ________
9 4-Digit Add
4,958
Work: Ans: ________
10 4-Digit Sub
7,032
− 4,685
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 8
Progress Probe Nine Assessment 09
Progress Probe Nine
Multi-Digit Operations • Form 9
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
49
Work: Ans: ________
2 2-Digit Sub
83
− 39
Work: Ans: ________
3 3-Digit Add
278
Work: Ans: ________
4 3-Digit Sub
641
− 275
Work: Ans: ________
5 3-Digit Add
589
Work: Ans: ________
6 3-Digit Sub
812
− 456
Work: Ans: ________
7 Across Zero
904
− 538
Work: Ans: ________
8 Double Zero
700
− 384
Work: Ans: ________
9 4-Digit Add
5,786
Work: Ans: ________
10 4-Digit Sub
8,103
− 4,756
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 9
Progress Probe Ten Assessment 10
Progress Probe Ten
Multi-Digit Operations • Form 10
Score: _____ / 10
Name:
Date:
Time:
Accuracy: ____ %
Directions: Calculate each sum or difference. Clearly record all regrouping trades. 10 Items • Standardized
1 2-Digit Add
68
Work: Ans: ________
2 2-Digit Sub
92
− 48
Work: Ans: ________
3 3-Digit Add
384
Work: Ans: ________
4 3-Digit Sub
725
− 368
Work: Ans: ________
5 3-Digit Add
679
Work: Ans: ________
6 3-Digit Sub
953
− 478
Work: Ans: ________
7 Across Zero
805
− 439
Work: Ans: ________
8 Multiple Zeros
6,000
− 2,467
Work: Ans: ________
9 4-Digit Add
6,758
Work: Ans: ________
10 4-Digit Sub
9,032
− 4,785
Work: Ans: ________
Mastery Scale: 10=100% • 9=90% • 8=80% (Goal) • 7=70% • ≤6=Review Digit Dynamics • Form 10
