◆ Built for the digital SAT Math section

Master Desmos. Stop solving SAT Math the slow way.

The digital SAT hands every student a Desmos graphing calculator — and almost nobody is taught to use it. DesPrep is that training: solve real SAT problems in a live Desmos embed, get told exactly what to type, then watch an expert replay the fastest route.

Skills 1–2 free forever · No credit card · Cancel paid plans any time

19 official SAT skills1,235 problemsEvery one with a worked method
Practice · Linear Equations in One VariableQuestion 4 of 65
0:12
NotesCalculator
GUIDED PRACTICE

What is the solution to 3x + 7 = −2x − 8 ?

1y = 3x + 7
2y = 2x 8
x y-8-6-4-224-8-44(-3-2)
Open Desmos workspace
4medium

Answer review:

A−3You chose
B−2
C2
D3

Solved in 0:12 · target 30s · 2 expressions

Covers all four College Board domainsAlgebraAdvanced MathProblem Solving & Data AnalysisGeometry & Trigonometry
The difference

Same question. Two ways to answer it.

What is the smaller solution to x² + 3x − 28 = 0 ?

By hand

~2:00
  1. 1Look for two numbers that multiply to −28 and add to 3.
  2. 2Try pairs: 1 and 28, 2 and 14, 4 and 7… land on 7 and −4.
  3. 3Write it as (x + 7)(x − 4) = 0.
  4. 4Set each bracket to zero: x = −7 or x = 4.
  5. 5Re-read the question — it asked for the smaller one.

Five chances to make a sign error, and none of them is the math you are being tested on.

The Desmos way

0:20
  1. 1Type it in.y = x2 + 3x − 28
  2. 2Click the left-hand point where the curve crosses the x-axis.
  3. 3Read it: (−7, 0)
x y-8-6-4-2246-30-20-10

No factoring, nothing to sign-error, and the answer is a point you can see.

There are 1,235 problems in here, and every one of them has a route like this. Read how the method works, or try the first two skills free →

How it works

Most students open Desmos on test day and freeze.

Here is what happens instead, on every single problem.

01

You solve it for real

A real Desmos calculator opens beside the question — the same one Bluebook gives you. You type, drag and click in it exactly as you would on test day.

02

You are told what to type

Each problem carries a worked method: the reasoning, the formula behind it, and the exact Desmos line to enter. Stuck is a state you can leave.

03

You watch the expert route

After you answer, the fastest path replays step by step against your own attempt — with your time next to the target, so you can see where it went.

Courses

Learn the skill before you drill it.

Practice alone only tells you what you got wrong. Every one of the 19 skills also has a written lesson — what the College Board is really testing, the fastest Desmos route through it, and the mistakes that cost the marks.

Why it is on the test

How often the skill appears in the 44 questions, what it is worth, and what being slow at it actually costs you later in the module.

The fast Desmos route

The method, with the exact keys — including the ones the instructions usually leave out, like the arrow that gets you back out of a fraction.

Where points get lost

Every wrong answer choice on the SAT is built from a real mistake. Each lesson names the ones this skill invites, and how to not make them.

Check you have it

A few questions to answer before you start, with the answers hidden until you commit. Fresh questions, so they do not spoil the practice set.

Free to read, from the moment you sign up

Linear Equations in One Variable

Free

An equation asks where two expressions are worth the same. Graph the left side and the right side as two separate lines, click where they cross, and read off the coordinate the question actually asked for.

12 min read · 6 parts · 6 mistakes to avoid

Linear Functions

Free

A linear function is a straight line, so every question about one is really a question about a point on that line. Graph the line, pin down the coordinate you were given, and read off the coordinate you were asked for.

12 min read · 6 parts · 6 mistakes to avoid

19 lessons, about 232 minutes of reading in total. Start with the free ones →

The curriculum

All 19 official SAT Math skills

Not a selection of tricks — the College Board's own list, every skill with about 65 problems graded easy to hard. Start with the first 2, free forever.

1,235 problems in total. Start with the free guide to using Desmos on the SAT, or unlock all 19

Pricing

Simple and honest

Start free. No credit card required, ever, for the free tier.

Free

$0 forever
  • Skills 1–2, complete
  • Live Desmos embed
  • Expert replays
  • The other 17 skills
Get started free
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Monthly

$9.99 /mo
  • All 19 skills
  • 1,235 SAT problems
  • Step-by-step feedback
  • Weekly progress email
Get monthly access

Cancel any time — stops the next charge. No refunds.

Lifetime

$49 once
  • Everything in Monthly
  • Pay once, keep forever
  • Future skills included
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Five months of monthly, and then it's yours

Questions

Before you sign up

Is Desmos really allowed on the SAT?

It is built into the test. The digital SAT runs in College Board’s Bluebook app, and a Desmos graphing calculator is available on every question in the Math section — no need to bring anything. That is exactly why knowing it well is worth so much: the tool is already there, and most students barely touch it.

Do I need to know Desmos already?

No. The first two skills are free and start from typing your first expression. Every problem tells you what to type, what to click, and what to read off the screen.

How is this different from Khan Academy or a prep book?

They teach you the math. This teaches you the calculator as a test-taking strategy — which questions to graph instead of solve, what to type, and which point to click. And you practice inside a real Desmos calculator rather than reading about one.

What if I am already scoring well in Math?

Then the gain is time rather than technique. Graphing a question you could already do by hand takes seconds instead of a minute, and that time goes to the questions where you actually need it.

What do I get for free?

The first two skills, complete — every problem, the live calculator, the step feedback and the expert replays. No credit card, and no trial that quietly expires.

Can I cancel?

Monthly cancels any time from your account page and keeps working to the end of the period you have paid for. Lifetime is a single payment with nothing to cancel. Cancelling stops the next charge — it is not a refund of one already made.

Do you offer refunds?

No. All purchases are final, on Monthly and Lifetime alike. That is exactly why skills 1–2 are free and complete, with no credit card — try the real thing first and only pay if it works for you.

The calculator is already on your test.

Two complete skills, free forever — enough to find out whether this changes how you sit the Math section.

Create your free account →

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