AP Precalculus Calculator Policy: The Essential Rules
When You Can and Cannot Use a Calculator
The AP Precalculus exam is divided into two sections, each containing a sub-section where technology is strictly prohibited. Section I (Multiple Choice) consists of Part A, where calculators are forbidden, and Part B, where a graphing calculator is required. Similarly, Section II (Free Response) begins with Part A, which allows calculator use, followed by a no calculator section AP Precalculus candidates must complete in Part B. This structure is designed to test separate cognitive domains. In the non-calculator sections, the focus is on analytical expressions and exact values, such as evaluating trigonometric functions at special angles of the unit circle or identifying vertical asymptotes from a rational function's denominator. In contrast, the calculator-active sections require students to handle "messy" real-world data where solutions are often irrational numbers requiring rounding to three decimal places. Understanding this transition is critical for time management; once the proctor signals the end of a calculator section, the device must be placed under the desk immediately.
The Strict Ban on CAS and Internet-Connected Devices
While technology is integrated into the curriculum, the College Board maintains a hard line against devices that automate symbolic manipulation. This is the primary reason for the ban on Computer Algebra System (CAS) functionality. A CAS-enabled device can perform symbolic factoring, symbolic differentiation, and solve equations in terms of variables (e.g., solving $ax^2 + bx + c = 0$ to yield the quadratic formula). Because AP Precalculus assesses a student's ability to perform these algebraic transformations manually, CAS models are strictly prohibited. Furthermore, any device with communication capabilities—including smartphones, tablets, or calculators with built-in Wi-Fi or Bluetooth—is banned to maintain exam integrity. If a student is found using an unauthorized device, their score is subject to immediate cancellation. The goal is to ensure a level playing field where the tool assists in numerical computation rather than replacing the student's conceptual understanding of algebraic structures.
List of Approved Graphing Calculators
Texas Instruments Models (TI-84 Plus, TI-Nspire non-CAS)
Texas Instruments remains the most common choice among exam-takers, with the TI-84 for AP Precalculus being the industry standard. The TI-84 Plus, TI-84 Plus Silver Edition, and the TI-84 Plus CE (Color Edition) are all fully compliant. These models are favored for their intuitive interface when handling list-based statistics and function graphing. Additionally, the TI-Nspire (non-CAS) and TI-Nspire CX are permitted. These devices offer higher-resolution screens and more robust file management systems, which can be advantageous when visualizing complex transformations of periodic functions. However, students must be cautious: the TI-Nspire CX II CAS is a different model entirely and is not permitted. The distinction lies in the "CAS" label usually printed in the upper right corner of the handheld. If that label is present, the device cannot enter the testing center.
Casio and HP Approved Models
Beyond Texas Instruments, there are several other approved calculators for AP Precalculus from Casio and HP. The Casio FX-9750GII and FX-9860GII are popular budget-friendly options that satisfy all exam requirements, including the ability to find intersections and calculate numerical derivatives. The Casio Prizm (CG10/CG50) series provides a color interface similar to the TI-84 CE. For HP users, the HP Prime is a powerful option, but it must be set to "Exam Mode" to disable prohibited features. It is important to note that scientific calculators, while sometimes allowed on other exams, do not meet the graphing requirement for AP Precalculus. The exam specifically asks questions that require a screen capable of displaying multiple function plots simultaneously to identify points of intersection or relative extrema that cannot be easily found through manual substitution.
How to Verify Your Calculator is Allowed
Verification is a multi-step process that should happen weeks before the exam date. Students should consult the official College Board AP Calculator Policy website, which maintains a comprehensive, alphabetical list of every permitted model. When checking the list, pay close attention to the suffixes; a "TI-89 Titanium" is prohibited while a "TI-84 Plus" is allowed. If a model is not explicitly listed, it is generally safer to assume it is not permitted. Furthermore, schools often conduct a pre-exam check. During this check, the proctor will verify the model number and ensure the device does not have an external QWERTY keyboard, which is another disqualifying feature. If you are using a borrowed device, ensure you are familiar with its specific firmware versions, as some older models may lack the MathPrint functionality necessary to display fractions and exponents in a readable format.
Prohibited Calculator Features and Functions
Why Computer Algebra Systems (CAS) Are Banned
The prohibition of CAS models is rooted in the specific assessment objectives of the Precalculus curriculum. A significant portion of the exam tests the ability to manipulate logarithmic and exponential expressions using the Change of Base Formula or Power Property. A CAS calculator can simplify $\log_2(8x^3)$ to $3 + 3\log_2(x)$ instantaneously. If such devices were allowed, the College Board would be unable to verify if a student understands the underlying logarithmic identities. The exam focuses on the student's ability to construct a mathematical model; the calculator is intended only to evaluate that model. For example, in a Free Response Question (FRQ), you might be expected to set up an equation like $500e^{0.05t} = 1500$. While you use the calculator to find the numerical value of $t$, you must show the algebraic steps leading to $\ln(3) = 0.05t$ to earn full credit on the scoring rubric.
Unacceptable Apps, Programs, and Stored Data
Beyond the hardware itself, the software environment inside the calculator is strictly regulated. The graphing calculator rules AP Precalc candidates must follow explicitly forbid the use of custom programs that solve specific types of problems, such as a "Quadratic Formula Solver" or a "Synthetic Division" app. While most calculators come with factory-installed Apps (like Finance or Conics), any third-party software that provides an unfair advantage is prohibited. Furthermore, students are not allowed to store notes, formulas, or "cheat sheets" in the calculator's memory or within the "Notes" application on models like the TI-Nspire. During the security check, proctors may look for archived variables or text files. The presence of such data is considered a violation of the Academic Integrity policy, potentially leading to a score of zero and a ban from future AP testing.
Mandatory Calculator Preparation Before Exam Day
Clearing Memory and Resetting Your Device
One of the most critical logistical steps is the mandatory clearing of the device's Random Access Memory (RAM). On a TI-84, this is typically done via the [2nd] [MEM] [7] [1] [2] sequence. Resetting the memory deletes all variables (A through Z) and any custom programs. It also restores the calculator to its default settings, which is a double-edged sword. While it ensures compliance, it also resets the Angle Mode to Radians. Since AP Precalculus heavily emphasizes radian measure for trigonometric functions and polar coordinates, this is usually beneficial. However, if a specific problem requires Degree mode, the student must remember how to toggle this setting manually. Failure to clear memory before the exam starts can be flagged as a security risk, and proctors are instructed to verify that the "RAM Cleared" screen is visible or that the LED indicator on newer models is flashing the appropriate "test mode" color.
Bringing Backup Batteries and a Spare Calculator
Technical failure is a rare but catastrophic event during high-stakes testing. The College Board does not provide backup devices, and proctors are not permitted to lend their own equipment. Therefore, the AP Precalculus calculator policy allows students to bring a second approved graphing calculator as a backup. If you choose to bring two, both must be cleared and placed on the floor under your desk; you may only have one on your workspace at a time. For those using the TI-84 Plus CE or TI-Nspire CX, ensure the lithium-ion battery is fully charged the night before. If using a model with AAA batteries, such as the standard TI-84 Plus, install a fresh set 24 hours prior and carry an extra pack in your bag. A dead battery mid-section can result in the loss of several points on the FRQ Part A, where numerical approximations are required for completion.
Practicing with Your Specific Model
Familiarity with your device's syntax is just as important as knowing the math. For instance, the way a calculator handles regression models varies significantly between brands. On a Casio, you might enter data into a List Editor and select "GRPH" then "CALC," whereas on a TI-84, you use the STAT menu followed by CALC and LinReg(ax+b). During the exam, you cannot afford to spend three minutes searching for the "intersect" command under the CALC menu. You should be able to find the zeros of a function or the point of intersection between a sinusoidal graph and a linear trend line within seconds. Practice using the TABLE feature to look for patterns in function growth (linear vs. exponential) and ensure you understand how to adjust the WINDOW settings so that all relevant features of a graph—such as local extrema and intercepts—are clearly visible on the screen.
Key Calculator Functions for AP Precalculus Success
Graphing and Analyzing Functions
The primary use of the calculator is the visualization of function behavior. You must be proficient at entering functions into the $Y=$ editor and selecting an appropriate viewing window. In AP Precalculus, you will often encounter functions with large coefficients, such as $f(x) = 150 imes (1.05)^x$. A standard $[-10, 10]$ window will show nothing. You must use the ZoomFit tool or manually adjust Ymax to see the y-intercept at $(0, 150)$. Beyond simple viewing, you must use the calculator to identify the domain and range of restricted functions. For example, when modeling the height of a ferris wheel over time, the calculator helps determine the interval of the range $[min, max]$ by using the maximum and minimum solvers. This visual confirmation is essential for answering multiple-choice questions regarding function transformations and periodicity.
Finding Roots, Intersections, and Maxima/Minima
Many questions in Section I, Part B require solving equations that are not easily factorable. You must be adept at using the 2nd [CALC] [zero] function to find the x-intercepts of a polynomial or the 2nd [CALC] [intersect] function to find where two models meet. For instance, if asked to find when a population reaching 5,000 based on the model $P(t) = 2000e^{0.1t}$, you would graph $Y1 = 2000e^{0.1t}$ and $Y2 = 5000$ and find their intersection. The calculator functions allowed on AP exam include these numerical solvers, which provide the precision required by the scoring guidelines. Remember that the College Board requires answers to be accurate to three decimal places. Relying on the trace cursor is insufficient; you must use the built-in solver functions to ensure the required level of precision for the final answer.
AP Precalculus places a heavy emphasis on data modeling, specifically linear, exponential, logarithmic, and sinusoidal regressions. You must be able to input a data set into lists (usually $L1$ and $L2$) and execute a regression command to find the line of best fit. A common exam task involves comparing two different models—such as a linear model and a power model—to determine which better fits a set of residuals. You should know how to view the coefficient of determination ($r^2$) on your device to justify your choice of model. If $r^2$ is closer to 1, the model is generally a better fit. Understanding how to interpret these outputs is key to the Free Response Questions, where you may be asked to "write the equation of the regression model" and then use that model to predict a value outside the given data set (extrapolation).
Exam Day Logistics: Calculator Check-In and Use
Procedures at the Start of the Calculator Sections
When the exam transitions from the non-calculator section to the calculator-active section, there is a specific protocol. The proctor will instruct you to take your calculator out from under your desk. At this point, they may walk through the aisles to perform a visual check of the models. You should have your device turned on and ready. This is the moment to ensure your Graphing Mode is set to "Function" (or "Polar/Parametric" if the question demands) and that your diagnostics are turned on if you anticipate doing regressions. Because the transition is timed, having your device ready to go prevents the loss of valuable minutes. It is also the time to check that your screen contrast is adjusted correctly for the room's lighting, as a dim screen can lead to reading errors during the high-pressure environment of the test.
What to Do If Your Calculator Malfunctions
If your calculator freezes or the screen goes blank, remain calm. First, try a soft reset (on TI models, this is often [2nd] [on] or pulling one battery). If the device is completely unresponsive and you brought a backup, quietly switch to the backup device. If you do not have a backup, raise your hand and notify the proctor. While they cannot give you a new calculator, they need to be aware of the situation in case you need to file an Irregularity Report. In the absence of a working calculator, pivot your strategy to solve as much of the problem as possible algebraically. Even in calculator-required sections, many points are awarded for the "setup" of the problem. Write down the equations you would have entered and describe the process you would have used (e.g., "I would find the intersection of $f(x)$ and $g(x)$ to determine the time $t$"). This may allow you to salvage partial credit.
Storing Your Calculator During No-Calculator Parts
One of the most common ways students accidentally violate the graphing calculator rules AP Precalc proctors enforce is by leaving their device on their desk during Section I, Part A or Section II, Part B. The rule is absolute: when the calculator is not permitted, it must be completely out of sight. Usually, this means placing it on the floor directly beneath your chair. Do not put it in your pocket or leave it in your lap, as this can be interpreted as an attempt to use it. Proctors are trained to look for the glow of a calculator screen during the non-calculator portions. Even if you are just checking the time or a previous calculation, having the device out is a grounds for dismissal. Discipline yourself to move the device as soon as the command is given to "put away all calculators."
Strategic Use of Your Calculator on the Exam
Balancing Calculator and Mental Math Efficiency
A common pitfall for advanced students is using the calculator for operations that are faster to do mentally. For example, if you need to find $f(0)$ for the function $f(x) = 3x^2 + 5x - 9$, typing this into the calculator is a waste of 15 seconds; the answer is clearly $-9$. The AP Precalculus calculator policy is intended to assist with complex tasks, not to replace basic arithmetic. Use your mental math for simple evaluations and save the calculator for solving for $x$ when $f(x) = 0$ or for calculating the average rate of change over an interval with decimal endpoints. This balance is critical for finishing the 28 multiple-choice questions in Part A and the 12 questions in Part B within the restrictive time limits. Every second saved on a simple calculation is a second earned for a complex modeling problem.
Avoiding Over-Reliance on the Calculator
Over-reliance can lead to "calculator blindness," where a student accepts an answer that is logically impossible because they made a syntax error. If you are calculating the height of a building and your calculator gives a negative number, you likely missed a sign in your entry or your window is showing the wrong part of the graph. Always perform a sanity check on your calculator's output. In the FRQ section, the calculator is a tool to get the final number, but the "work" is the algebraic setup you write on the paper. If you only provide the answer without the supporting mathematical setup, you will receive a score of 0 for that part of the question, regardless of whether the answer is correct. The calculator provides the "what," but your written work must provide the "how."
Time-Saving Calculator Techniques
To maximize efficiency, utilize the Variable Storage feature. If you find a point of intersection $x = 1.45832...$, store that value as variable $A$ using the STO> key. This allows you to use the exact value in subsequent calculations without having to re-type a long string of decimals, which reduces the risk of rounding errors. Another technique is using the Y-VARS menu to evaluate functions. Instead of re-typing a complex function multiple times, you can type it once into $Y1$ and then use $Y1(5)$, $Y1(10)$, etc., to find values at different points. These small technical shortcuts can save several minutes over the course of the exam, providing you with a significant advantage in the Section I Part B multiple-choice section where time is often the greatest challenge.