To prepare for TSIA2 math, study for the 20-question test, not the 48-question one. Everyone sits the College Readiness Classification (CRC) Test first, and a CRC score of at least 950 is the state’s mathematics readiness standard. Seven of the 25 content subcategories in the specification appear only on the Diagnostic Test you are routed to after falling short — so time spent on them does nothing for the score that decides your placement.
Brilliant is the understanding layer here and the state’s published materials are the exam layer. Brilliant teaches most of the mathematics the specification describes, by making you solve problems rather than watch explanations. It does not teach the exam: no adaptive-format walkthrough, no practice tests, no strategy.
What does the TSIA2 math test actually test?
TSIA2 Mathematics is two adaptive, computer-delivered, multiple-choice tests drawing on four content categories: Quantitative Reasoning, Algebraic Reasoning, Geometric and Spatial Reasoning, and Probabilistic and Statistical Reasoning. The CRC Test is 20 items — 6 quantitative, 7 algebraic, 3 geometric and 4 probabilistic-and-statistical — reported on a 910 to 990 scale. Score below the standard and you are routed into the 48-item Diagnostic Test, 12 items per strand, which reports a level from 2 to 6 plus a basic, proficient or advanced descriptor in each strand.
The readiness rule itself is in Texas administrative rule, effective January 11, 2021: for college-level coursework with a mathematics-intensive designation, you need a CRC score of at least 950, or a CRC score below 950 together with a Diagnostic level of 6. Either route counts, which is why the Diagnostic Test is worth understanding rather than dreading.
You may not use a handheld calculator of any type. Some — not all — of the questions carry a pop-up calculator on screen.
Before you study at all, check whether you have to test. Entering students who meet a TSI exemption do not: the exemptions include college-readiness benchmarks on the SAT or ACT, the STAAR English III or Algebra II end-of-course exams, and completing the high school College Preparatory Course.
What is not on the test is worth as much as what is. There is no calculus, no vectors, no matrices, no complex numbers and no polar coordinates. Trigonometry stops at right-triangle ratios, so the unit circle, radians and identities are out, and logarithms are named nowhere in the specification. There is no formal proof, no statistical inference, no correlation or regression, and no conditional probability or expected value. Calculus, Vectors and Complex Numbers are worth none of your TSIA2 hours, and Logarithms and Trigonometric Functions contribute one matched skill each.
The Diagnostic-only distinction, and why it decides your plan
Seven subcategories — plain arithmetic with whole numbers, decimals and fractions; rounding to a place value; comparing and ordering numbers; identifying standard units; identifying angle types; sorting and counting data; and constructing simple graphs and tables — appear on the Diagnostic Test only. They are the below-grade-level content it reaches down to, and the CRC Test never asks about them.
That has a direct consequence for how you use Brilliant. Of the 433 matched skills on the coverage page, 33 sit on those seven subcategories — and all 14 of the matches in Fractions are among them. Fractions is a good course; if your goal is to clear 950, it is not where your hours belong. Work it only if you are headed for the Diagnostic Test and need your level to reach 6.
Which of that math does Brilliant teach?
Brilliant lessons reach 21 of the 25 content subcategories — 433 matched skills across 829 distinct lessons in 28 courses.
- Quantitative Reasoning. Ratios and unit rates in Proportional Reasoning, percent increase, decrease and reversal in Percents, everyday price scaling and formula writing in Real-World Algebra, magnitudes, roots and scientific notation in Exponents and Radicals, and manipulating and interpreting linear expressions, equations and inequalities in Solving Equations, Linear Relationships and Visual Algebra.
- Algebraic Reasoning. Multi-step solving in Linear Equations, substitution and elimination in Linear Systems, factoring, completing the square and the quadratic formula in Quadratics, polynomial arithmetic in Polynomials, rational and radical expressions in Equations and Curves, and compound interest in Exponential Functions.
- Geometric and Spatial Reasoning. Perimeter, circumference, surface area and volume in Geometry and Measurement, translations, reflections, rotations and dilations in Coordinate Transformations, and distance, area on a grid, circles and the Pythagorean theorem in Coordinate Geometry.
- Probabilistic and Statistical Reasoning. An event and its complement in Probability and Chance, mean, median, mode and spread in Everyday Statistics, and choosing, reading and reasoning from charts in Exploring Data Visually.
The subcategory-by-subcategory version of this is on the TSIA2 math coverage page.
Where is Brilliant strongest for the CRC?
On Algebraic Reasoning, which is also the largest share of the CRC Test at 7 of its 20 items. Manipulating quadratic, polynomial, exponential, rational and radical expressions is the most heavily matched subcategory in the whole framework, and solving linear equations and systems is close behind. Add the linear expression work TSIA2 files under Quantitative Reasoning, and the algebra of the CRC Test is the part Brilliant prepares you for best.
Geometric and Spatial Reasoning is the thinnest — fittingly, since it is only 3 of the 20 CRC items. All of Brilliant’s perimeter, area, surface area and volume work for this test lives in a single 25-lesson course.
What will you not get from Brilliant?
Unit conversion is the one real gap, and it is CRC-level. TSIA2 makes “convert units within systems of measurement” a subcategory of its own, and Brilliant teaches no measurement-unit conversion anywhere in its math catalog — not inches to feet, not milliliters to liters. A prep book or a conversion table will close it in an afternoon; nothing on Brilliant will.
Three other subcategories have no Brilliant lessons behind them — rounding to a given place value, identifying standard units of measurement, and constructing simple graphs and tables. All three are Diagnostic-only, so they cost you nothing on the CRC Test and matter only if you are working toward a Diagnostic level of 6.
Then there is the exam layer, which Brilliant does not attempt: the adaptive format, the pop-up calculator, and any timed or full-length practice.
What should you study, and in what order?
Work the categories in CRC weight order, heaviest first. Every row is CRC content; the Diagnostic-only subcategories are deliberately absent.
| Content category | What the CRC asks for | Start here |
|---|---|---|
| Algebraic Reasoning — 7 of 20 items | Solving linear equations, inequalities and systems; evaluating linear functions; manipulating and solving quadratic, polynomial, exponential, rational and radical expressions; quadratic and exponential contexts | Combining Terms |
| Quantitative Reasoning — 6 of 20 | Magnitudes of rational and irrational numbers; ratios, proportions and percents; applied proportional and financial reasoning; manipulating and interpreting linear expressions | Working out Percentages |
| Probabilistic and Statistical Reasoning — 4 of 20 | Probability of an event and its complement, measures of center and spread, classifying data and choosing a representation, drawing conclusions from given data | Means |
| Geometric and Spatial Reasoning — 3 of 20 | Unit conversion, perimeter, area, surface area and volume, transformations used to investigate congruence and similarity, right-triangle relationships, coordinate geometry | Perimeters |
If you are short on time, do the first two rows and stop: 13 of the 20 CRC items come from them, and they are the two categories Brilliant covers most deeply. Open individual lessons rather than completing courses — Brilliant lessons are short and stand on their own, so you can go straight to the topic that cost you points.
What should you use from the state?
The Texas Higher Education Coordinating Board and College Board publish the TSIA2 Mathematics Test Specifications, which lists every content subcategory and marks the Diagnostic-only ones, and a student informational brochure describing the testing experience and the calculator policy. The score standard itself lives in Texas administrative rule. Read the specification once before you study: knowing which category each of the 20 CRC items comes from is worth more than another hour of practice questions.
Is Brilliant a complete TSI prep course?
No. Brilliant is not a TSI prep course, is not affiliated with or endorsed by the Texas Higher Education Coordinating Board or College Board, and does not include practice tests, timing drills, or score guarantees. It teaches the mathematics the test is checking you on. Use Brilliant for the math and the state’s official materials for the exam, and you have both halves.
How this mapping was made
Brilliant’s curriculum team maps skills to TSIA2’s content subcategories skill by skill against the live course catalog, using the TSIA2 Mathematics Test Specifications as the authority on what each subcategory requires and which ones the CRC Test does not assess. The data behind this page was pulled on September 23, 2026 and reflects the catalog on that date.
Frequently asked questions
What score do I need?
For college-level coursework with a mathematics-intensive designation, a CRC score of at least 950, or a CRC score below 950 plus a Diagnostic level of 6. The CRC scale runs from 910 to 990.
Do I have to take the TSI at all?
Not if you meet an exemption. Qualifying SAT or ACT scores, the STAAR English III or Algebra II end-of-course exams, and the high school College Preparatory Course can all exempt you. Check before you spend a month studying.
Can I use a calculator?
Not your own. Handheld calculators of any type are not permitted, and some questions provide a pop-up calculator on screen instead.
My fractions are shaky. Should I fix that first?
Only if you are aiming for a Diagnostic level of 6. Fraction arithmetic and ordering are Diagnostic-only content, so they cannot appear on the CRC Test — though you will still need fluency with fractions inside the algebra questions that can.
Related resources
- TSI Assessment (TSIA2) math coverage: Brilliant lesson mapping by subcategory
- Texas TEKS math coverage: Brilliant lesson mapping by standard
- How to prepare for the GED math test
- What math does Brilliant cover?
- Explore Brilliant’s courses
Sources
[1] College Board, prepared for the Texas Higher Education Coordinating Board, TSIA2 Mathematics Test Specifications (Version 1.4), and the TSIA2 Student Informational Brochure, accessed September 2026.
[2] Texas Higher Education Coordinating Board, 19 Texas Administrative Code § 4.57, College Ready Standards, and the Texas Success Initiative program page, accessed September 2026.
[3] Brilliant, standards alignment database, pulled on September 23, 2026.
[4] Brilliant, “TSI Assessment (TSIA2) math coverage: Brilliant lesson mapping by subcategory”, accessed September 2026.
[5] Brilliant, “Courses”, accessed September 2026.
