Diagnosis
Identify the gap, error pattern, or misconception.
Built by a working classroom teacher
See what students understand. Know what to do next.
The Pragmatic Teacher brings together the Recalculation Method™, the Matthie Mathematics Education Series, Matthie Assessment, books, AI tools, and professional learning into one practical system for better mathematics decisions.
Grades 7–9 focusSkill-first resourcesBooks + classroom tools + AI
4core mathematics books
2Recalculation books
48current TPT resources
20+years in classrooms
Start here
What are you trying to do?
Tell us what you're trying to do, and we'll point you straight there.
The Recalculation Method™
A repeatable response to what happens after “wrong.”
The same five steps apply whether the gap shows up in a worksheet, a diagnostic, or a conversation with a student.
A wrong answer should trigger a better instructional decision—not merely a lower mark.
Reframing
Treat the error as evidence and a next step.
Reteaching
Use a precise explanation, representation, or task.
Retesting
Check again with a parallel task.
Integration
Reconnect the corrected idea to future learning.
The whole platform
One philosophy. Multiple ways to use it.
Everything below traces back to the same classroom question: what do I teach next?
The Pragmatic Teacher
The public home for ideas, tools, books, courses, and resources.
PLATFORMThe public home for ideas, tools, books, courses, and resources.
The Recalculation Method™
The teaching and assessment philosophy connecting everything.
CORE METHODThe teaching and assessment philosophy connecting everything.
Matthie Mathematics Education Series
The instructional spine: Number Sense, Algebra, Proportional Reasoning, and Geometry.
Matthie Assessment
The diagnostic-response system: screen, diagnose, teach, check, reassess, and track.
RecalculatingThe foundational professional book.
Recalculating with AIAI as support for teacher judgment.
Recalculation CourseImplementation and professional learning.
Free Teacher ToolsDiagnostic starter + AI prompts.
Matthie Mathematics Education Series
The Math Series. One connected mathematics pathway.
The books become the instructional spine. Assessment resources then reveal what students understood and where instruction should go next.
Number Sense
Understanding quantity, place value, patterns, and mathematical relationships.
Coming SoonAlgebra
Expressions, equations, inequalities, linear graphing, systems, polynomials, and factoring.
Coming SoonProportional Reasoning
Fractions, decimals, percents, ratios, and rates.
Coming SoonGeometry I
2-D foundations: measurement, shapes, area, angles, and circles.
Coming SoonGeometry II
Pythagorean reasoning and 3-D measurement: right triangles, nets, surface area, volume, and capacity.
Coming SoonMatthie Assessment — real evidence
Show what makes the resources different.
See the diagnosis before you buy the resource.
ALGEBRA I
Q1 Solve for x: 4x + 6 = 26
Ax = 8
Bx = 5
Cx = 20
Dx = 16
Algebra I — Student Sampler
Each wrong answer is mapped to a specific algebra error, sign mistakes, skipped steps, operation confusion.
Integers & Rational Numbers — Teacher Edition
Each wrong answer is mapped to a named misconception, with a 60-second correction and a Recalculating link.
PERCENTAGE CHANGE · Q1
$40 → $50. Percent increase?
Opt
Answer
Diagnostic meaning
A
20%
Used the new price as the base
B ✓
25%
Correct, increase ÷ original
C
10%
Reported the dollar change as the percent
D
125%
Forgot to subtract the 100% baseline
Percentage Change Pack
Each wrong answer is mapped to a specific error, wrong base, unit confusion, or skipped subtraction.
Diagnostic value
One answer. One clue. One next move.
10 − 2 × 3 = ?
Opt
Answer
Diagnostic meaning
A
24
Order of operations error — subtracted before multiplying
B ✓
4
Correct — multiplied before subtracting
C
8
Dropped the multiplication entirely
D
16
Multiplied correctly, then added instead of subtracting
Teacher move: ask which operation happens first, then have the student redo it in two visible steps.
How it actually works
One click tells you the next move.
1Write an answer
Student answers the question, same as any assessment.
2Move on
No pause, no re-teaching mid-quiz, the student keeps going.
3Wrong answer flagged
The specific wrong choice is matched to a named misconception.
4Next step shown
You get the exact teacher move, not just a score.
Skill-first resource finder
Skill first. Purpose second. Grade range third.
Search by the math skill you're teaching, not by a single grade label.
No sample resources match those filters.
Books, AI & professional learning
The platform is bigger than the student worksheets.
The books and course behind the method, for teachers who want the full system, not just the printables.
Recalculating
The professional foundation for diagnosis, dignity, “Not Yet,” reassessment, and responding to student error.
Recalculating with AI
Use AI to strengthen planning, analysis, feedback, differentiation, and teacher efficiency without surrendering professional judgment.
Learn & Implement the Method
A professional-learning pathway for individual teachers, teams, coaches, and school leaders who want to implement the full system.
Get the Course →Free entry points
Experience the value before buying.
Start with the order of operations set. It shows how every Matthie Assessment resource treats a wrong answer: as a clue, not a verdict.
Free download
Order of Operations: 4 Common Mistakes + Anchor Chart
The four mistakes students make most often, each with the wrong work, the likely cause, and the fix. Also includes an anchor chart for BEDMAS and PEMDAS, guided notes, and a 4-question Quick Check with a diagnostic answer key. Grades 6-9. Enter your email and it arrives in your inbox.
Free on TPT
Free Diagnostic Samples
See the diagnostic approach in action: every wrong answer linked to a likely cause, with a short correction move.
AI teacher tool
25 AI Prompts for Teachers
Practical prompts for planning, differentiation, assessment, feedback, and classroom workflow. Enter your email to get the full kit.
Built from classroom need
A teacher's system for answering: “What do I teach next?”
The books, math series, diagnostic tools, course, and AI work all come from the same practical classroom question.
“I didn't create Recalculation because students were failing tests. I created it because a test score wasn't telling me what I needed to teach tomorrow.”Connect on LinkedIn →
Contact
Get in touch.
Questions about the course, resources, or professional learning? Contact Carlington Matthie by email or WhatsApp.
Using webmail? Copy the address into a new message.
Teach. Diagnose. Recalculate. Master.
One platform connecting mathematics instruction, diagnostic evidence, teacher learning, AI support, and the next instructional move.