What this exam actually asks of you
The TACHS is about 200 questions in six separately timed sections, and every section closes when its time is up. You cannot go back. For a thirteen-year-old used to school tests where you can flip back through the paper, that single rule causes more lost marks than any topic on the syllabus.
The mistake that ruins the result
Running it untimed "just to see how she does". It produces a lovely score and tells you nothing, because the one thing the TACHS punishes is not noticing that a section is nearly over.
How to sit it
Enforce all six clocks, in order, in one sitting of about two and a half hours. Put a real clock on the table. When a section closes, close it, even mid-question, because that is what will happen.
What to do the day after
Look first at how many questions were left blank in each section rather than at how many were wrong. Blanks are a pacing problem and they are the cheapest thing to fix.
What a practice test owes you
The TACHS reports percentile ranks rather than marks, so a raw practice score compares to nothing the real exam will send you. What a sitting can give you is where the time went and which wrong answers were guesses.
Our TACHS bank holds 1,200 questions and 3,900 wrong answers, and every one of those wrong answers carries its own sentence saying what a student who picked it was probably thinking. Not one is left bare, and a build of our site fails if that stops being true. On the TACHS the Ability sections are where those sentences earn their keep, because a child who cannot see why a figure does not belong learns nothing from being told they were wrong.
We also measure whether the paper can be beaten without being read. On our TACHS exams the best any length-based strategy scores is 37%, against the 25% that pure guessing gives. A practice test where picking the longest option beats guessing is measuring the person who wrote it, not your child.
The three Ability sections are where practice pays most, because nothing in a New York eighth-grade classroom resembles a paper-folding question and unfamiliarity is doing the damage rather than difficulty.
Where to sit one
We publish six full TACHS forms with no questions shared between them, each sat under the same six section clocks as the real paper. A free sample is on the samples page, and it needs no account.
More on this exam: the full TACHS guide, the Ability sections, how TACHS scoring works.
Common questions
How long should a TACHS practice test take?
About two and a half hours across six separately timed sections, sat in order.
Should a TACHS practice test be timed?
Yes, all six clocks. An untimed TACHS run hides the only mistake this exam reliably punishes.
Is the score the useful part of a TACHS practice test?
No, the reasons are. Every one of the 3,900 wrong answers in our TACHS bank carries a sentence saying what a student who picked it was probably thinking, and for TACHS that is what turns a list of misses into a plan.
How often should we sit a TACHS practice test?
Twice is plenty. We publish six forms so a second and third sitting are genuinely new papers, not a memory test.
Practice the real thing
Our TACHS exams are full length and written from scratch — every wrong answer carries its own explanation, so a child learns what they got wrong and why. Ten questions are free, with no account and no card. After that it is five credits an exam.