Use the graphing view of Desmos on the SAT when a question gives you a table, a graph, two equations or data to model. Switch to the scientific calculator for plain arithmetic, especially when you want a fraction answer or a trig value in degrees. Bluebook lets you move between the two at any point in the Math section, so you can pick per question.
To try both on the College Board setup, open the practice calculator on our Desmos on the SAT page. Below you'll find the decision rule, one worked case for each mode, and the mistakes that cost points.
The decision rule
Read the question before you open anything. Then ask one thing: does the answer depend on a picture or a data set, or only on a number?
| If the question has | Open | Why |
|---|---|---|
| A table of values, or asks for a model or line of best fit | Graphing | Desmos fits a regression from a table with a tilde (~). On the College Board version, log mode switches on by itself for exponential, logarithmic and power fits. |
| Two equations, or asks how many solutions a system has | Graphing | You can see where the graphs cross, or that they don't cross at all. |
| A graph to read: vertex, intercepts, a maximum or minimum | Graphing | You get the picture the question describes. |
| Arithmetic with fractions in the answer choices | Scientific | When a result can be written as a fraction, a fraction icon appears next to it. Click it and 2.125 becomes 17/8. |
| A trig value for an angle given in degrees | Scientific | The keypad has a RAD/DEG toggle, and Desmos lists degrees as the scientific calculator's default. |
| Very large or very small numbers | Scientific | It shows those results in scientific notation, and you can type numbers in scientific notation directly. |
| Combinations or permutations | Either | Both views accept nCr(n, r) and nPr(n, r). |
Desmos's College Board calculator sheet says the scientific and four-function calculators on your test don't differ from the ones on desmos.com. The graphing calculator loses images, folders and notes. So practice on desmos.com/scientific matches what you'll see in the scientific view on test day.
Worked case 1: fit a table (graphing)
SAT-style question. A lab records the mass of a culture, in grams, at hours 0, 1, 2 and 3: 500, 750, 1,125 and 1,687.5. An exponential model fits the data. What mass does the model predict at hour 5?
The question hands you a table and asks for a model, so open the graphing view. Enter the data in a table with columns x_1 and y_1, then type the model on a new line with a tilde in place of the equals sign.
You just learned when to switch modes. Now see those exact problem types on an SAT math section — free, no card needed.
Start 1-day free trial →2 y_1 ~ a b^(x_1)
3 a b^5
Line 2 returns a = 500 and b = 1.5. Desmos stores those values, so line 3 uses them without retyping and gives 3,796.875 grams.
Check it by hand. Each mass is 1.5 times the one before: 750 ÷ 500 = 1.5, 1,125 ÷ 750 = 1.5, and 1,687.5 ÷ 1,125 = 1.5. So the model is y = 500(1.5)^x, and 500 × 1.5^5 = 500 × 7.59375 = 3,796.875. Because this ratio comes out exact, you could also finish it in the scientific view. The table route earns its keep when the data doesn't follow a clean pattern. For more of these, work through our SAT regression practice problems on Desmos.
Worked case 2: two equations (graphing)
SAT-style question. The graphs of y = 3x - 4 and y = -2x + 11 intersect at the point (x, y). What is the value of x + y?
2 y = -2x + 11
The lines cross at (3, 5). Check both equations: 3(3) - 4 = 5 and -2(3) + 11 = 5. The question asks for x + y, so the answer is 8. Entering 3 or 5 answers a different question. If the two lines were parallel, they would never cross, and the system would have no solution. Our guide to solving systems of equations on Desmos has three more worked examples.
Worked case 3: a fraction answer (scientific)
SAT-style question. If (2/3)x = 5/4 + 1/6, what is the value of x? A) 17/12 B) 17/8 C) 9/4 D) 17/4
No graph, no table: one number. Switch to the scientific calculator. Multiply both sides by 3/2 and type the right side.
The result shows 2.125. Click the fraction icon next to it and it reads 17/8, which is choice B. By hand: 5/4 + 1/6 = 15/12 + 2/12 = 17/12, and 17/12 × 3/2 = 51/24 = 17/8. Choice C is 2.25, close enough to fool you if you round early, so compare the fraction rather than a rounded decimal.
Worked case 4: trig in degrees (scientific)
SAT-style question. A ramp 20 feet long rises at a 35° angle to the ground. To the nearest tenth of a foot, how high is its top end above the ground?
See which question types are costing you points
Start with a free mock, free drills, or preview sample questions before using all 45 question banks.
The height is the side opposite the 35° angle, and the ramp is the hypotenuse, so the height is 20 sin 35°. Before you type, check that the scientific keypad shows DEG, not RAD.
In degrees the result is 11.4715..., so the answer is 11.5 feet. In radians the same keys give about -8.56, and a negative height tells you the setting is wrong. If you'd rather stay in the graphing view, it has its own Radians and Degrees toggle under Graph Settings. We could not confirm which angle setting Bluebook's calculator starts in, so check it before any trig question.
Either view: combinations
SAT-style question. How many different 3-person committees can be chosen from 8 people?
Type nCr(8, 3) in either view and you get 56. Desmos lists nCr and nPr among the graphing calculator's functions as well as the scientific calculator's, so you don't need to switch for a counting question. In the scientific view you can also type 8!/(3!*5!) and get the same 56. If order mattered, as with a president, a secretary and a treasurer, you would use nPr(8, 3) = 336. An earlier version of this page said the graphing view has no nCr. That was wrong, and we have removed it.
Guided example: you finish it
SAT-style question. A video had 200, 260 and 338 hundred views on days 0, 1 and 2. An exponential model fits. How many views, in hundreds, does the model predict on day 4?
Step 1: the question gives a table, so open the graphing view. Step 2: enter days as x_1 and views as y_1. Step 3: type y_1 ~ a b^(x_1). Desmos returns a = 200 and b = 1.3. Step 4 is yours: type the line that gives the prediction for day 4.
Check your answer
Type a b^4. The model predicts 200 × 1.3^4 = 571.22 hundred views, about 57,122 views. By hand: 260 ÷ 200 = 1.3 and 338 ÷ 260 = 1.3, so each day multiplies the views by 1.3.
Your turn
SAT-style question. A 12-foot ladder leans against a wall and makes a 40° angle with the ground. How high up the wall does the ladder reach, to the nearest tenth of a foot? Pick your view before you type.
Show the answer
Use the scientific view in degrees: 12 sin(40) gives 7.713..., so about 7.7 feet. If you got 8.9, your calculator was in radians. That wrong answer is positive and looks reasonable, so the angle check matters even when nothing looks off.
When algebra is faster
College Board's calculator policy says some Math questions are better done without a calculator, even though you're allowed one. Case 2 is a good example: 3x - 4 = -2x + 11 gives 5x = 15 and x = 3 in two lines. Graph it only if you want to check your work. Get your setup on scratch paper first, then choose the view that fits the last step.
Mistakes to avoid
- Rounding in the middle. If you round 1.5^5 to 7.59, you get 500 × 7.59 = 3,795 instead of 3,796.875. Use the stored a and b in the graphing view, or the ans key in the scientific view.
- The wrong angle setting.
20 sin(35)gives 11.47 in degrees and about -8.56 in radians. Check DEG before any degree question. - Answering the point instead of the question. The lines in case 2 cross at (3, 5), but the question asked for x + y, which is 8.
- Losing a number when you switch. Write any value you need on your scratch paper before you move to the other view.
Practice next
Try each case above on the College Board version of the calculator, then move to timed questions. If you're not sure which calculator Bluebook gives you, start with our guide to opening the College Board version of Desmos. For more graph reading, learn how to find x- and y-intercepts on Desmos.
Practice both views of Desmos
Open the College Board version of Desmos on our Desmos on the SAT page, run the four cases above, then practice on SAT Math questions.
Practice on the SAT version of Desmos
Next, practice SAT Math questions in the TTA question bank, or create a practice account.
Checked on September 26, 2026 against College Board's SAT Suite calculator policy, Desmos's College Board calculator sheet (marked "Updated for SY2026-2027"), and the Desmos Help Center's Scientific Calculator User Guide, Supported Functions, Regressions and Graph Settings pages. The questions on this page are SAT-style teaching examples written by TTA. The Test Advantage is independent of College Board and Desmos.
Frequently Asked Questions
Can I switch between scientific and graphing Desmos on the SAT?
Yes. College Board's calculator policy says students can toggle between the scientific and graphing options at any point in the Math section. Write down any number you need before you switch.
Is the SAT scientific calculator the same as desmos.com?
Yes. Desmos's College Board calculator sheet says the scientific and four-function calculators on the test don't differ from the ones on desmos.com. Only the graphing calculator changes: images, folders and notes are off.
Which Desmos mode should I use for regressions on the SAT?
Graphing. A regression needs the data in a table and a model typed with a tilde, such as y_1 ~ a b^(x_1). The College Board graphing calculator turns on log mode by itself for exponential, logarithmic and power regressions.
Can the Desmos graphing calculator do combinations (nCr)?
Yes. Desmos lists nCr and nPr among the graphing calculator's functions and the scientific calculator's. Type nCr(8, 3) in either mode to get 56.
Does the Desmos scientific calculator show fractions?
Yes. When a result can be written as a fraction, a fraction icon appears next to it. Click it to switch a result like 2.125 to 17/8, and click again to go back to the decimal.