Grid Subtraction Progress Monitoring Worksheet
Subtraction Progress Monitor
Place Value Grid & Base-Ten Modeling Probe
Probe Goal 3-Digit Subtraction
Score / 8
Student:
Date:
Probe #:
Interval: Wk ___
Model Key: Flat = 100 Rod = 10 Unit = 1
1. Draw top number • 2. Cross out bottom number
Part A
Subtraction Without Regrouping (Problems 1–4)
Align digits by place value
1 365 − 42
No Trade
−
H (100)
T (10)
O (1)
3
6
5
−
0
4
2
Draw Hundreds, Tens, & Ones Draw 365 • Cross out 42
Hundreds (□)
Tens (|)
Ones (•)
2 587 − 234
No Trade
−
H (100)
T (10)
O (1)
5
8
7
−
2
3
4
Draw Hundreds, Tens, & Ones Draw 587 • Cross out 234
Hundreds (□)
Tens (|)
Ones (•)
3 479 − 156
No Trade
−
H (100)
T (10)
O (1)
4
7
9
−
1
5
6
Draw Hundreds, Tens, & Ones Draw 479 • Cross out 156
Hundreds (□)
Tens (|)
Ones (•)
4 648 − 35
No Trade
−
H (100)
T (10)
O (1)
6
4
8
−
0
3
5
Draw Hundreds, Tens, & Ones Draw 648 • Cross out 35
Hundreds (□)
Tens (|)
Ones (•)
Part A Subtotal: ______ / 4 Correct Page 1 of 2 • Turn over for Part B (Regrouping)
Part B
Subtraction With Regrouping (Problems 5–8)
Student:
Date:
Trading Rules:
• Need more Ones? Trade 1 Ten for 10 Ones • Need more Tens? Trade 1 Hundred for 10 Tens
5 452 − 128
Trade 1 Ten
−
H (100)
T (10)
O (1)
Trade
4
5
2
−
1
2
8
Model & Unbundle 2 < 8 → Trade 1 Ten for 10 Ones
Hundreds (□)
Tens (|)
Ones (•)
6 627 − 284
Trade 1 Hundred
−
H (100)
T (10)
O (1)
Trade
6
2
7
−
2
8
4
Model & Unbundle 2 < 8 → Trade 1 Hundred for 10 Tens
Hundreds (□)
Tens (|)
Ones (•)
7 534 − 268
Double Trade
−
H (100)
T (10)
O (1)
Trade
5
3
4
−
2
6
8
Model & Unbundle Trade Tens → Ones, then Hundreds → Tens
Hundreds (□)
Tens (|)
Ones (•)
8 741 − 385
Double Trade
−
H (100)
T (10)
O (1)
Trade
7
4
1
−
3
8
5
Model & Unbundle 1 < 5 (trade ten) • 3 < 8 (trade hundred)
Hundreds (□)
Tens (|)
Ones (•)
Teacher Progress Monitoring Record & Analysis
Total Accuracy: ____ / 8 (____ %)
Skill Breakdown
Without Regrouping: ____ / 4
With Regrouping: ____ / 4
Base-Ten Drawing Model: ____ / 8
Diagnostic Observations
Subtracted smaller from larger Place value column shift Forgot to reduce unbundled ten Basic math fact error
Goal Status
Mastery (≥ 85%) Progressing (60-84%) Needs Support (< 60%)
Grid Subtraction Answer Key
Subtraction Progress Monitor
Teacher Answer Key
Place Value Grid & Base-Ten Model Solutions
Part A Solutions 1: 323 • 2: 353 • 3: 323 • 4: 613
Scoring: 1 pt algorithm accuracy • 1 pt base-ten model representation (2 pts/item = 8 pts Part A)
Part A: 8 Points
Part A
Solutions: Subtraction Without Regrouping (Problems 1–4)
Top digits ≥ bottom digits
1 365 − 42
Ans: 323
−
H (100)
T (10)
O (1)
—
—
—
—
3
6
5
−
0
4
2
•
3
2
3
Model Solution: Draw 365, Cross out 42 Left: 3 H, 2 T, 3 O
Hundreds (3)
100 100 100
Tens (6 − 4 = 2)
Ones (5 − 2 = 3)
× ×
2 587 − 234
Ans: 353
−
H (100)
T (10)
O (1)
—
—
—
—
5
8
7
−
2
3
4
•
3
5
3
Model Solution: Draw 587, Cross out 234 Left: 3 H, 5 T, 3 O
Hundreds (5 − 2 = 3)
100 100 100 × ×
Tens (8 − 3 = 5)
Ones (7 − 4 = 3)
× × × ×
3 479 − 156
Ans: 323
−
H (100)
T (10)
O (1)
—
—
—
—
4
7
9
−
1
5
6
•
3
2
3
Model Solution: Draw 479, Cross out 156 Left: 3 H, 2 T, 3 O
Hundreds (4 − 1 = 3)
100 100 100 ×
Tens (7 − 5 = 2)
Ones (9 − 6 = 3)
× × × × × ×
4 648 − 35
Ans: 613
−
H (100)
T (10)
O (1)
—
—
—
—
6
4
8
−
0
3
5
•
6
1
3
Model Solution: Draw 648, Cross out 35 Left: 6 H, 1 T, 3 O
Hundreds (6 − 0 = 6)
100 100 100 100 100 100
Tens (4 − 3 = 1)
Ones (8 − 5 = 3)
× × × × ×
Key Note: For Problem 4, verify the student preserved the 6 hundreds when subtracting the 2-digit number 35. Page 1 of 2 • Turn over for Part B Answer Key
Part B Key
Solutions: Subtraction With Regrouping (Problems 5–8)
Part B Quick Check: 5: 324 • 6: 343 • 7: 266 • 8: 356
Verification Focus: Confirm trade notation in top boxes: original digit slashed and decremented, next place value +10.
5 452 − 128
Ans: 324
−
H
T
O
Trade
—
4
12
4
5
2
−
1
2
8
•
3
2
4
Model: 1 Ten Traded → 10 Ones 12 − 8 = 4 Ones • 4 − 2 = 2 Tens
Hundreds (4 − 1 = 3)
100 100 100 ×
Tens (5 → 4 − 2 = 2)
→
Ones (2 + 10 = 12 − 8 = 4)
× × × × × × × ×
6 627 − 284
Ans: 343
−
H
T
O
Trade
5
12
—
6
2
7
−
2
8
4
•
3
4
3
Model: 1 Hundred Traded → 10 Tens 12 − 8 = 4 Tens • 5 − 2 = 3 Hundreds
Hundreds (6 → 5 − 2 = 3)
100 100 100 × × →T
Tens (2 + 10 = 12 − 8 = 4)
Ones (7 − 4 = 3)
× × × ×
7 534 − 268
Ans: 266
−
H
T
O
Trade
4
12
14
5
3
4
−
2
6
8
•
2
6
6
Double Trade (Tens → Ones, Hundreds → Tens) 14 − 8 = 6 • 12 − 6 = 6 • 4 − 2 = 2
Hundreds (4 − 2 = 2)
100 100 × × →T
Tens (12 − 6 = 6)
Ones (14 − 8 = 6)
× × × × × × × ×
8 741 − 385
Ans: 356
−
H
T
O
Trade
6
13
11
7
4
1
−
3
8
5
•
3
5
6
Double Trade (Tens → Ones, Hundreds → Tens) 11 − 5 = 6 • 13 − 8 = 5 • 6 − 3 = 3
Hundreds (6 − 3 = 3)
100 100 100 × × × →T
Tens (13 − 8 = 5)
Ones (11 − 5 = 6)
× × × × ×
Diagnostic Analysis & Targeted Interventions
Error: Top-Minus-Bottom Inversion
Wrote 8 − 2 = 6 instead of regrouping 12 − 8 = 4.
Next Step: Use concrete rods/units: "You only have 2 ones. Can you give me 8 without trading a rod?"
Error: Forgot to Decrement
Traded 1 ten for 10 ones, but left tens as 5 instead of 4.
Next Step: Teach "Slash & Reduce First": slash tens digit and write new value before unbundling ones.
Mastery & Progress Criteria
≥ 7 / 8 (≥ 85%): Goal Met. Ready for 4-digit or multi-step word problems.
Schedule: Bi-weekly probe if progressing; weekly if receiving Tier 2/3 SDI.
