Desmos for the SAT · Start here
What Desmos Is and Where It Lives on the SAT
The free graphing calculator built into the Digital SAT, and how to open it.
Two minutes on the basics before any technique: what Desmos is, when you get it, and how to open it.
Every lesson after this one assumes these three things.
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Once you know what Desmos is and how to pull it up, every move in this series is point and click.
Watch the lesson
Now you try
Every section below has a live calculator loaded with the same setup as the clip. Do each one yourself as you read, do not just skim it.
What Desmos is
Desmos is a free online graphing calculator. On the Digital SAT it is built into the Bluebook testing app, so there is nothing to download and nothing to bring. It is the same calculator as the one at desmos.com, minus a few extras such as notes, folders and pasting images, and nothing in this series uses those. Anything you practice at desmos.com transfers.
The same calculator is built into the digital PSAT/NMSQT and PSAT 8/9, so everything here applies there too.
Section 1You only get it on the Math section
The calculator is available the whole time on both Math modules. It is not there on the Reading and Writing section, and you do not need it there. So every Desmos move you learn is a Math move.
Section 2How to open it
During any Math module, click the Calculator button in the top toolbar. Desmos opens in a panel you can drag around and resize so it does not cover the question. Click the button again to tuck it away.
The panel has two tabs in its top left corner, Graphing and Scientific. It opens on Graphing, which is the one nearly every technique in this series uses. One click switches to Scientific, a plain calculator for the questions that are only arithmetic and never needed a graph.
You can also bring your own approved handheld calculator, but the built-in Desmos does things a handheld cannot, like graphing an equation and clicking the exact answer, which is the whole point of this series.
Section 3Practice it here, not only on test day
Our practice tests use the same Bluebook-style calculator in the same spot, so drilling with it here builds the muscle memory you want on test day. Do not save Desmos for the real thing; the students who win points with it are the ones who already know the moves cold.
Section 4Say hello to it
Here is the real thing, right on this page. Click into the box on the left and type y = 2x + 3, then watch Desmos draw the line the moment you finish. That instant feedback is the whole reason it wins you points. The next lesson is about everything else you can click.
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Type it, then change the 2 to a 5 and watch the line snap steeper. Desmos redraws the instant you type. That is the feeling to remember.
Type $y=2x+3$ and watch it draw. Nothing to set up; start typing.
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That is the orientation. Next: the handful of controls the SAT needs.
Now put it on a real SAT question
SAT Prep Quest drills let you practice these Desmos basics on real SAT questions, adapting to what you miss so nothing feels new on test day.
Practice freeSAT is a registered trademark of the College Board, which was not involved in producing, and does not endorse, this product. Score estimates are Learner Labs projections, not official College Board scores.