6 Desmos Hacks to Boost Your SAT Math Score

By Laura Whitmore

One of the most common things we hear from students preparing for the digital SAT is this: “I run out of time in Module 2, and the math questions at the end feel impossible.” If that sounds familiar, you’re not alone! The College Board has definitely increased the difficulty level of questions in the second math module—and unfortunately, their answer explanations can read more like a novel than a helpful guide.

The good news? There's a tool built right into the digital SAT that can make these problems much more manageable: Desmos.

When used strategically, Desmos can help students avoid careless mistakes, pick up quick points, and save time they can use to check their work later. And Desmos isn’t just for graphing functions—it can actually help with systems of equations, expressions with variables, regression problems, and even some geometry. Below are six real examples of how students can use Desmos more effectively to get a higher SAT Math score.

Not up for reading? Watch my YouTube video instead!

1. Systems of Equations with “r” in the Answer Choices

Here’s what to do:

✅ Graph both equations in Desmos.

✅ Then, type in the answer choices as coordinate pairs using r as a slider.

✅ The correct answer will trace the entire line on the graph.

This strategy is incredibly fast and accurate. Instead of working through a long algebraic solution, Desmos lets you visually confirm the answer in seconds.

2. Questions with One Constant Variable

you can:

✅ Assign a simple value to a (like 1) and enter the function into Desmos.

✅ Then, identify what the question is asking for—often it’s the y-value of a vertex.

✅ Plug that same value of a into each answer choice and see which one matches the vertex's y-value.

This only works when there's one variable in play. If the problem includes multiple constants (like a, b, and c), using Desmos might be more confusing than helpful.

3. Regression with a Table of Values

you can:

✅ Enter the values into a Desmos table.

✅ Use a regression command (y1 ~ mx1 + b for a linear function).

✅ Match the coefficients to the question.

Make sure you replace x and y with x1 and y1 in Desmos if you're using a table—that small detail matters.

4. Regression Without a Table

you can:

✅ Manually enter the points into a Desmos table.

✅ Use the appropriate regression format (e.g., y1 ~ a * b^x1 for an exponential function).

✅ Match the parameters provided in Desmos with what the question is asking—like finding the product of a and b.

5. Equivalent Expressions

Watch out for small errors like missed negative signs or incorrect parentheses—accuracy matters when using this approach.

6. Geometry Problems (Yes, Even These!)

Here’s an example:

✅ A triangle is equilateral, and you're given the total perimeter.

✅ You divide by three to get the side length.

✅ You then place the triangle on the coordinate plane and use geometry knowledge (like 30-60-90 triangle ratios) to find three exact points.

✅ Once you have those, you can run a circle regression in Desmos using the equation (x1 - h)^2 + (y1 - k)^2 ~ r^2.

If the question asks for something like “what is w if the radius is 3w,” all you do is take the value of r and divide it by 3.

Want to Learn More?

If you want a deeper dive into when to use Desmos (and just as importantly, when not to), we offer a Desmos Crash Course where we break down advanced techniques and walk through examples just like these.

We also cover Desmos strategies in our Self-Paced SAT Math Course, where students get video walk-throughs, guided practice, and more test-day tools to feel confident and prepared.

Whether you’re just starting your prep or pushing for a top score, using Desmos the right way can be a game-changer. The key is knowing when it can save you time—and when it might lead you down the wrong path.

Happy prepping!