Calculators You Can Use On The Act

Understand the official ACT calculator policy and know which calculators you can use on the ACT. We also provide a quadratic equation solver as an example of calculations you might perform on the ACT math section with permitted calculators.

Quadratic Equation Solver (ax² + bx + c = 0)

This calculator solves for ‘x’ in a quadratic equation, a common task you might use an approved calculator for on the ACT math test.

The roots of a quadratic equation ax² + bx + c = 0 are given by the formula: x = [-b ± √(b² – 4ac)] / 2a. The term b² – 4ac is the discriminant.

Summary of ACT Calculator Policy Highlights (Always check the latest official ACT policy)

Calculator Feature/Type	Allowed on ACT?	Notes
Four-function	Yes	Basic arithmetic operations.
Scientific	Yes	With exponents, logs, trig functions.
Graphing	Yes (most models)	Must NOT have QWERTY keyboard or CAS (Computer Algebra System) unless CAS is disabled. Check ACT’s list.
Calculators with QWERTY keyboards	No	e.g., TI-92, Voyage 200
Calculators with built-in CAS	No (unless CAS is disabled or removed)	e.g., TI-Nspire CAS, HP Prime, Casio ClassPad. Some Nspire models are allowed if CAS is off.
Calculators on phones, tablets, laptops	No	No electronic devices other than permitted calculators.
Calculators that make noise or print	No	Must be silent and non-printing.

What are Calculators You Can Use on the ACT?

Calculators you can use on the ACT refer to the specific types and models of calculators that are permitted for use during the mathematics section of the ACT test. The ACT has a strict calculator policy that outlines which devices are allowed and which are prohibited. The main goal is to ensure fairness and prevent students from having an unfair advantage through advanced calculator features like Computer Algebra Systems (CAS) or communication capabilities.

Students taking the ACT should carefully review the official ACT calculator policy before test day to ensure their calculator is compliant. Generally, most four-function, scientific, and graphing calculators are allowed, provided they don’t have prohibited features like a QWERTY keyboard or an enabled CAS. Understanding the calculators you can use on the ACT is crucial for test preparation.

Who Should Understand This Policy?

Any student planning to take the ACT test, particularly the mathematics section, must be fully aware of the calculator policy. Parents, teachers, and tutors guiding students through ACT preparation also need to understand which calculators you can use on the ACT to provide accurate advice.

Common Misconceptions

• “All graphing calculators are allowed”: This is false. Many advanced graphing calculators with CAS or QWERTY keyboards are banned or restricted.
• “The test center will provide a calculator”: The ACT does NOT provide calculators; students must bring their own permitted device.
• “I can use my phone’s calculator”: Absolutely not. Phones and other communication devices are strictly prohibited during the test.
• “A more expensive calculator is always better”: While a familiar graphing calculator can be helpful, knowing how to use it efficiently for ACT-relevant problems is more important than having the most advanced features, especially since some advanced features are banned. Many students do very well with a standard scientific calculator.

Quadratic Formula and Mathematical Explanation

The quadratic formula is used to find the roots (solutions) of a quadratic equation in the form ax² + bx + c = 0, where a, b, and c are coefficients and a ≠ 0. This is a typical problem you might solve using calculators you can use on the ACT.

The formula is derived by completing the square on the standard quadratic equation:

1. Start with ax² + bx + c = 0
2. Divide by a: x² + (b/a)x + (c/a) = 0
3. Move c/a to the right: x² + (b/a)x = -c/a
4. Complete the square for the left side: Add (b/2a)² to both sides: x² + (b/a)x + (b/2a)² = -c/a + (b/2a)²
5. Factor the left side: (x + b/2a)² = (b² – 4ac) / 4a²
6. Take the square root of both sides: x + b/2a = ±√(b² – 4ac) / 2a
7. Isolate x: x = -b/2a ± √(b² – 4ac) / 2a
8. Combine: x = [-b ± √(b² – 4ac)] / 2a

The term b² – 4ac is called the discriminant. It tells us about the nature of the roots:

• If b² – 4ac > 0, there are two distinct real roots.
• If b² – 4ac = 0, there is one real root (a repeated root).
• If b² – 4ac < 0, there are no real roots (two complex conjugate roots).

Variables in the Quadratic Formula

Variable	Meaning	Unit	Typical Range
a	Coefficient of x²	None	Any real number except 0
b	Coefficient of x	None	Any real number
c	Constant term	None	Any real number
x	Variable or unknown	None	The roots/solutions
b² – 4ac	Discriminant	None	Any real number

Practical Examples (Real-World Use Cases on the ACT)

While the ACT math section uses word problems, they often boil down to solving equations, including quadratics.

Example 1: Finding Dimensions

A rectangular garden has an area of 50 sq ft. The length is 5 ft more than the width. Find the width.
Let width = w, then length = w + 5. Area = length × width, so w(w+5) = 50, which is w² + 5w – 50 = 0.
Here, a=1, b=5, c=-50.
Using the calculator (or formula):
Discriminant = 5² – 4(1)(-50) = 25 + 200 = 225
x = [-5 ± √225] / 2 = [-5 ± 15] / 2
x1 = (-5 + 15)/2 = 10/2 = 5
x2 = (-5 – 15)/2 = -20/2 = -10
Since width cannot be negative, the width is 5 ft.

Example 2: Projectile Motion

The height H of an object thrown upwards after t seconds is given by H(t) = -16t² + 64t + 80. When does the object hit the ground (H(t)=0)?
We solve -16t² + 64t + 80 = 0. We can simplify by dividing by -16: t² – 4t – 5 = 0.
Here a=1, b=-4, c=-5.
Discriminant = (-4)² – 4(1)(-5) = 16 + 20 = 36
t = [4 ± √36] / 2 = [4 ± 6] / 2
t1 = (4 + 6)/2 = 5
t2 = (4 – 6)/2 = -1
Time cannot be negative, so the object hits the ground after 5 seconds.

Knowing which calculators you can use on the ACT allows you to perform these calculations quickly and accurately.

How to Use This Quadratic Equation Calculator

1. Enter Coefficient ‘a’: Input the number that multiplies x² in your equation into the ‘Coefficient a’ field. Remember ‘a’ cannot be zero.
2. Enter Coefficient ‘b’: Input the number that multiplies x into the ‘Coefficient b’ field.
3. Enter Constant ‘c’: Input the constant term into the ‘Constant c’ field.
4. View Results: The calculator will instantly display the discriminant, and the roots x1 and x2 (if they are real) in the ‘Results’ section. The primary result will summarize the roots found.
5. See the Graph: A visual representation of the parabola y=ax²+bx+c is shown, illustrating the real roots as intersections with the x-axis.
6. Reset: Click ‘Reset’ to return the coefficients to their default values.
7. Copy Results: Click ‘Copy Results’ to copy the input coefficients and the calculated results to your clipboard.

This tool is useful for practicing the types of quadratic equations you might encounter and solve using calculators you can use on the ACT.

Key Factors That Affect ACT Calculator Use & Math Performance

When considering calculators you can use on the ACT and your math section performance, several factors come into play:

• Familiarity with Your Calculator: Knowing your calculator’s functions well before the test is crucial. Wasting time figuring out how to use it during the ACT is detrimental.
• Calculator Policy Compliance: Ensuring your calculator is on the permitted list and doesn’t have banned features is the first step. Check the official ACT website for the latest policy on calculators you can use on the ACT.
• Speed and Accuracy: A calculator can speed up calculations, but only if you input the numbers and operations correctly. Double-check your entries.
• Knowing When to Use It: Not every problem requires a calculator. Some are faster to solve mentally or with simple paper-and-pencil work. Over-reliance can slow you down.
• Battery Life: Make sure your calculator has fresh batteries or is fully charged.
• Understanding the Math Concepts: The calculator is a tool; it doesn’t replace the need to understand the underlying mathematical concepts being tested on the ACT. You need to know *what* to calculate.
• Practice: Use your permitted calculator while doing ACT practice tests to get used to the types of problems and how your calculator can help.

Frequently Asked Questions (FAQ)

What are the basic types of calculators allowed on the ACT?

Four-function, scientific, and most graphing calculators are allowed. However, restrictions apply, especially for graphing calculators with advanced features.

Are TI-84 Plus calculators allowed on the ACT?

Yes, the TI-84 Plus family (including Plus C Silver Edition, CE) is generally permitted as it does not have a built-in Computer Algebra System (CAS).

Are TI-Nspire calculators allowed on the ACT?

The TI-Nspire (non-CAS) is allowed. The TI-Nspire CAS is NOT allowed unless the CAS functionality is completely disabled (which may involve removing or disabling it before the test in a verifiable way, often difficult).

Can I use a calculator with a QWERTY keyboard?

No, calculators with typewriter-like (QWERTY) keyboards are prohibited.

What is a CAS (Computer Algebra System)?

A CAS can perform symbolic manipulation (like factoring, solving equations symbolically). Calculators with CAS are generally prohibited or restricted on the ACT.

Where can I find the official ACT calculator policy?

On the official ACT website (act.org). Always check the latest policy before your test date as it can be updated. This is the definitive source for calculators you can use on the ACT.

What if my calculator is not on the permitted list but I think it’s okay?

It’s risky. If it has prohibited features (QWERTY, CAS, etc.), it will not be allowed. If unsure, bring a backup calculator that is clearly permitted or contact ACT directly well before the test day.

Do I need a graphing calculator for the ACT?

No, it’s not required. A scientific calculator is sufficient for all math problems on the ACT. However, if you are very familiar with a permitted graphing calculator, it can be helpful for some problems.