Skill by Skill Prep: master the digital SAT one skill at a time
Skill by Skill Prep is the independent companion website to Skill by Skill: Digital SAT Study Guide 2027. It breaks the digital SAT into the 30 skills the test actually measures, finds your weakest ones with a free 49-question diagnostic, teaches each with a method and worked examples, gives you 370 chapter questions with an AI coach beside you, and rehearses test day with two timed full-length practice tests of 98 questions each.
The test in one minute
The digital SAT has two sections, Reading and Writing and then Math, each split into two separately timed modules. The second module of each section is easier or harder depending on how you did on the first. There is a 10-minute break between the sections, no penalty for wrong answers, and a calculator is allowed on every Math question.
Reading and Writing: 2 modules of 27 questions, 32 minutes each (54 questions in 64 minutes)
Math: 2 modules of 22 questions, 35 minutes each (44 questions in 70 minutes)
1. Find your starting point. Take the 49-question diagnostic. Your skill map shows which of the 30 skills to study first and which you can move through quickly. Free in the study workspace, and printed in the book.
2. Learn one skill at a time. Each skill chapter shows what the question looks like, how to recognize it, a step-by-step method, worked examples, the common traps and the harder-module variations. 4 chapters are free; every skill has a free public guide with two video lessons.
3. Practice with an AI coach beside you. Answer 370 chapter questions with every answer choice explained. Stuck? The coach gives a hint without the answer; after you check, it walks you through the method and answers follow-up questions. A free account includes 10 coach requests.
4. Rehearse under real timing. Take Practice Test 1 with four timed modules and the 10-minute break, tag every miss by type, study what it shows, then take Practice Test 2 on fresh questions. Both tests are printed in the book and timed in the workspace.
5. Walk in ready. Use the time budget for each module, the two-pass method, the test-day checklist and the device rules. The test-day guide is free.
Stuck on a practice question? Ask the coach. Before you check your answer it gives hints and guiding questions without revealing the answer. After you check, it explains why the right answer works, why your choice was tempting, and how to recognize the question type next time, and it answers your follow-up questions. It works only on this site’s original questions and is off during the diagnostic and the timed tests, as on test day.
What is included
33 chapters: how the test works, a study plan, pacing, one chapter for each Reading and Writing skill, the Math skills grouped into 14 chapters, and two full test reviews
615 original questions: 370 chapter questions, a 49-question diagnostic and 2 full-length practice tests of 98 questions each
81 typed-answer Math questions checked with the official entry rules
Every answer choice explained, with steps and a calculator option for Math
94 original figures, graphs and tables
A mistake log built on five miss types: content gap, trap, misread, careless and time
An AI study coach that gives hints before you check and explanations after (10 free requests with an account)
68 hand-picked video lessons: two for every skill
Free, no payment needed
The 49-question diagnostic with a skill map
A 10-question practice sampler with explanations and coach hints
4 full chapters: the test at a glance, Words in Context, the Math toolkit and Linear Equations in One Variable
A public guide for each of the 30 skills
68 video lessons
Format, scoring, typed-answer, study-plan and test-day guides
A free account saves your work and adds 10 AI coach requests
These studies describe learning in general, mostly with school and college students. None tested this test or this site, and no study, book or practice test can promise a score.
Test yourself instead of rereading. Students who took practice tests remembered more on delayed tests than students who restudied, even though restudying made them feel more confident. A major review of ten study techniques rated only two as high utility: practice testing and spaced practice. Here, every chapter ends with closed-book practice, and you commit to an answer before you see the explanation. (Roediger & Karpicke, 2006; Dunlosky et al., 2013)
Spread your study out. Across 317 experiments, spacing study sessions apart beat massing the same time together, and the best gap grew as the test got further away. Here, the error log brings each miss back for a redo after a few days and again after about a week. (Cepeda et al., 2006)
Learn from explanations, not just scores. Across 435 studies, feedback helped learning on average, and feedback that carries more information helped more. Right-or-wrong alone carries little. Here, every question explains the right answer and why each wrong choice fails, and the AI coach answers your follow-up questions. (Wisniewski, Zierer & Hattie, 2020)
Judge readiness by evidence, not by feel. People who score lowest tend to overestimate how well they did, and how easy practice feels is a poor guide to what you will remember later. Here, you predict your range before each full-length test and compare it with the result; Practice Test 2 is a fresh check after you study Practice Test 1’s misses. (Kruger & Dunning, 1999; Soderstrom & Bjork, 2015)
Is Skill by Skill Prep affiliated with the College Board?
No. It is an independent study website and book. SAT® is a trademark registered by the College Board, which is not affiliated with, and does not endorse, this website or book. All questions and explanations are original and were written for this book.
What does the free version include?
The 49-question diagnostic, a 10-question practice sampler, 4 full chapters, a public guide for every one of the 30 skills, 68 video lessons, and the format, scoring, typed-answer and test-day guides. A free account saves your work and adds 10 AI coach requests.
How does the AI coach work?
It is a study coach powered by Google Gemini that only works on this site’s original practice questions. Before you check an answer it gives hints and guiding questions without revealing the answer. After you check, it explains why the right answer works, why your choice was tempting and how to spot the question type next time. It is turned off during the diagnostic and the timed practice tests, as on test day. It can make mistakes, so the written explanation is always the final word.
Are the practice tests adaptive like the real test?
No. The real test chooses an easier or harder second module from your first-module performance. This book’s Practice Test 1 and Practice Test 2 are fixed, with a somewhat harder second module, so they cannot produce official scores. After each test you get a wide, clearly unofficial range for study planning.
Can I type math answers the way the real test requires?
Yes. Typed-answer questions use the official entry rules: up to 5 characters for a positive answer and 6 with a minus sign, fractions or decimals, no mixed numbers, commas or symbols. The answer box tells you when an entry would not be accepted.
Can I use a calculator?
On the real test a calculator is allowed on every Math question, and the Bluebook app includes the Desmos graphing calculator. The practice tests here link to Desmos’s free test-mode calculator so you can practice with the same tool.
How long does it take to prepare?
The book’s study plan offers several plan lengths built from the diagnostic, your target and the weeks you have. Whatever the length, take the diagnostic first, work the skills where you lose the most points, and space your two full-length tests so you have time to study between them.
Is the book available in print?
The book, Skill by Skill: Digital SAT Study Guide 2027 by Matthew D. Giron, MBA, is being prepared for Amazon in paperback and Kindle. The book page will link to it when it is live. The book is complete on its own; you never need this website to use it.
How much does the full workspace cost?
Paid plans open soon. The planned prices are $19.99 a month or $49.99 for three months, each with 300 AI coach requests a month. Everything listed as free stays free.
How current is the information?
The book’s exam specifications were checked against official College Board pages on 29 October 2026. Corrections and announced changes are listed on the updates page.
Independence
Skill by Skill Prep is an independent study website and book. SAT® is a trademark registered by the College Board, which is not affiliated with, and does not endorse, this website or book. Bluebook™ is a trademark of the College Board. Desmos is a trademark of Desmos Studio PBC. Practice results and ranges are study estimates, not official scores or admission predictions.