The SAT has 179 skills.
We track every one.
Most SAT prep tells you "review Algebra." Praczo tells you exactly which algebra skill is costing you points — and gives you targeted practice to fix it.
Broad topics aren't enough.
Knowing you're “weak in Algebra” is like knowing you feel sick somewhere. Useful for knowing something is wrong — useless for knowing how to fix it.
Test results
You got 8 of 22 Math questions wrong.
You still don't know which algebra skill is the problem.
Test results — exact concepts
You know the exact skill. You know the fix. You know what to do next.
Domain → Subtopic → Concept
Praczo organizes the entire SAT into a three-level hierarchy. At the top are domains — the four broad areas the College Board tests. Each domain contains subtopics. Each subtopic contains the individual concepts — the specific, teachable skills that separate right answers from wrong ones.
A concept is small enough to master in a single study session. It's big enough to represent a real skill — not a trivia fact, but a pattern of reasoning you either have or you're building.
- Every concept has a mastery score (0–100%)
- Every concept has a short lesson you can read on demand
- Every concept links directly to practice questions targeting it
- Mastery decays over time — spaced repetition built in
A school store sells pencils for $0.75 each and erasers for $0.50 each. Kenji buys 10 items total and pays $6.25. How many pencils did he buy?
Concepts tested by this question
Every question knows what it's testing.
Before a question goes live on Praczo, it gets tagged to one or more specific concepts. That tagging is what makes everything downstream possible — the mastery scores, the targeted drills, the study plan.
When you get a question wrong, Praczo doesn't just mark it red. It records which concept you missed, nudges your mastery score for that concept down, and flags it for your next study session. One wrong answer = one data point. Fifty wrong answers = a picture of exactly where you stand.
How a wrong answer updates your profile
A score for every skill.
Updated in real time.
Every concept gets a mastery score from 0 to 100, calculated from your recent accuracy on questions tagged to that concept. It's recency-weighted — what you practiced last week matters more than what you did a month ago.
Needs work
Core gaps. Concept lesson + immediate drill.
Developing
Inconsistent. More reps to build reliability.
Proficient
Solid. One full-test appearance to confirm.
Mastered
Move on. Spaced review keeps it sharp.
Setting up equations from word problems
Needs work
Factoring quadratics
Needs work
Subject-verb agreement
Proficient
Similar triangles
Developing
Contrast transitions
Mastered
Finding textual evidence
Mastered
Percent change
Developing
Pronoun-antecedent agreement
Proficient
Concept lesson
Setting up equations from word problems
The key idea
Word problem questions don't test arithmetic — they test your ability to translate English into algebra. The SAT always gives you enough information; your job is to assign a variable and write the right equation before you solve anything.
The 3-step method
- 1.Name what you don't know — assign one variable
- 2.Write one equation from the total or rate given
- 3.Solve and check against both conditions
Worked example
“Tickets cost $12 for adults and $8 for children. If 30 tickets were sold for $300, how many adult tickets were sold?”
Let a = adult tickets
a + (30 − a) = 30 ✓
12a + 8(30 − a) = 300
4a = 60 → a = 15
Understand it.
Then practice it.
Every concept comes with a short, focused lesson — a 2–5 minute read that explains exactly what the concept is, how it shows up on the SAT, and the clearest way to approach it. No fluff, no padding.
The lesson isn't a separate resource you have to go find. It surfaces right inside the practice flow — when you miss a question, when you start a concept drill, or any time you tap “Read lesson” from your concept map.
- One concept per lesson — laser focused
- 2–5 minute read, no videos required
- Always followed by 3–5 targeted practice questions
- Available on demand from your concept weakness map
179 concepts.
Every SAT skill, mapped.
Here's the full breakdown across all 8 domains. No SAT skill falls outside this map.
Algebra
- Setting up equations from word problems
- Slope-intercept form
- Systems of linear equations
- Linear inequalities
- Absolute value equations
- + 7 more
Advanced Math
- Factoring quadratics
- Vertex form of a parabola
- Polynomial long division
- Exponential growth & decay
- Rational expressions
- + 13 more
Problem Solving & Data
- Interpreting scatterplots
- Mean, median, mode
- Probability basics
- Two-way tables
- Percent change
- + 9 more
Geometry & Trigonometry
- Similar triangles
- Circle theorems
- Volume of 3D solids
- Pythagorean theorem
- Right triangle trigonometry
- + 15 more
Craft & Structure
- Words in context (vocabulary)
- Author's purpose
- Identifying tone and perspective
- Text structure (compare/contrast)
- Transition words
- + 17 more
Information & Ideas
- Central idea and details
- Finding textual evidence
- Inferences from text
- Interpreting data in passages
- Comparing paired passages
- + 23 more
Standard English Conventions
- Subject-verb agreement
- Pronoun-antecedent agreement
- Comma usage
- Apostrophes & possession
- Run-on sentences
- + 30 more
Expression of Ideas
- Contrast transitions
- Adding relevant information
- Eliminating redundancy
- Combining sentences
- Rhetorical goal of a revision
- + 25 more
Find out which concepts
are holding you back.
Take the 25-minute diagnostic. Get your personal mastery map across all 179 concepts. Start fixing the right things from day one.
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