Top 10 Features of the TI-84 Series for Taking the Enhanced ACT Math Test
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About the author: Tom Reardon taught every math course at Fitch High School (Ohio) during his 35-year career, where he received the Presidential Award and attained National Board Certification. He was an adjunct mathematics and computer science instructor at Youngstown State University for 38 years. Since 2009, Reardon has been a senior math advisor for TI in product strategy and development. |
The ACT test has undergone some important enhancements in 2025. Let’s review the main changes to the math portion of the test, as well as 10 of my favorite features of the TI-84 series that help students do their best work on the ACT.
The TI-84 series is allowed during the entire portion of the math section of the ACT. You can use your TI graphing calculator to work through problems more efficiently, help verify answers and model a difficult word problem.
My favorite TI-84 features that help students demonstrate what they know include:
- Calculate Logarithms With Different Bases
- Solve Any Equation With Numeric Solver
- Solve Any Inequality (Linear, Quadratic, etc.) Using the Graphing Feature
- Calculate Complex Numbers
- Evaluate Functions
- Evaluate Expressions Involving More Than One Variable
- Absolute Value – Discover Math Conceptually, Graphically, Visually
- Compute Fractions
- Solve Systems of Equations Graphically
- Solve Systems of Linear Inequalities Graphically
Legacy ACT vs. Enhanced ACT
There are now just 45 questions on the math section of the ACT, and students only have 50 minutes to complete them. The questions get more difficult as the problem number increases, so you should aim to do questions #1-15 in 30 seconds each, 16-30 in 60 seconds each, and #31-45 in 90 seconds each, on average.
These tables highlight the main changes to the ACT math test.
Updates to the ACT Math Test
| Legacy ACT | Enhanced ACT |
|---|---|
| 60 questions | 45 questions |
| 60 minutes | 50 minutes |
| 5 answer choices | 4 answer choices |
| Paper test | Digital or paper test (for the foreseeable future) |
| Italicized or capitalized words | Bolded words |
Math Rebalanced Reporting Categories
(Number of questions instead of percentages)
| Category |
Legacy ACT (60 questions) |
Enhanced ACT (45 questions) |
|---|---|---|
|
Preparing for Higher Math (High school math) |
34-60 | 36 |
| • Number | 5-7 | About 5 |
| • Algebra | 7-9 | 8-9 |
| • Functions | 7-9 | 8-9 |
| • Geometry | 7-9 | 8-9 |
| • Statistics and Probability | 5-7 | 5-7 |
|
Integrating Essential Skills (Middle school math) |
24-26 | 9 |
| Modeling | 16+ | 9+ |
| Field test items |
Extra section (standalone) |
4 questions (integrated) |
1. Calculate Logarithms With Different Bases
The TI-84 will calculate logarithms with any base – including bases that are fractions or even irrational numbers. To access the “log to any base” template:
- Press [alpha].
- Press [window] (f2).
- Select option 5: logBASE(.
2. Solve Any Equation With Numeric Solver
You can use the Numeric Solver to solve any equation. For example:
Solve: 4(2x + 3) = ½(9 - 4x)
Here’s how you access the Numeric Solver:
- Press [math].
- Press [up arrow] [enter].
- Enter the left side into E1 and the right side into E2. Press [graph] for OK.
- Enter initial guess after X =
- Press [graph] to solve.
Note: You can also use the “decimal to fraction” template. Follow these steps:
- Press [alpha].
- Press [y=] then [4].
- Press [enter] after the decimal answer.
3. Solve Any Inequality (Linear, Quadratic, etc.) Using the Graphing Feature
Another tip using your TI-84 is to solve inequalities using the graphing feature. For example:
Solve: 4 – 3x < 9 – 2x
To accomplish this, first turn Detect Asymptotes on:
- Press [2nd] [zoom](format).
- Press [up arrow].
In Y₁ field, type the inequality as it’s shown and recall that the inequality symbols are available by typing [2nd] [math] (test). Then press [zoom] [4] to view the graph.
The solution is: x > – 5.
4. Calculate Complex Numbers
If you come across a problem that uses complex numbers — fear not!
You can change the TI-84 to a + bi (complex mode). Do this by pressing the [mode] key on your calculator. On the 7th row, you’ll see the a + bi (complex mode). Once you switch your calculator to that mode, you can add, subtract, multiply, and divide complex numbers. You can even calculate the powers of i.
5. Evaluate Functions
On the ACT math test, you are often asked to evaluate functions and composition of functions. You can save time by using a feature on the TI-84 series that you normally use to graph functions. For example, you might see a problem like this:
If a(x) = 3x-2 and b(x) = x² +4 then b(a(4)) = ?
You can store the functions in Y₁ and Y₂ to help you answer this question. Follow these steps:
- Press [y=].
- In the Y₁ field, enter in the first function: 3x-2.
- In the Y₂ field, enter in the second function: x² +4.
Then on the home screen, you can use that to do b(a(4)), which in this case would be Y₂ (Y₁ (4)). You can find Y₁ and Y₂ by pressing the [alpha] key and then [trace] (f4).
Now that you know this tip, you can use it to do simple things like evaluating functions, or take it to the next level and add, subtract, multiply and divide functions. You can even evaluate the composition of functions like in the example.
6. Evaluate Expressions Involving More Than One Variable
Sometimes you will need to evaluate expressions on the ACT math test. In the screenshot below, you can see an example on how to evaluate various expressions for A = – 4 and B = – 3. This is possible by using the [sto→] key on the TI-84. You can use this feature to assign or store values to a variable.
7. Absolute Value – Discover Math Conceptually, Graphically, Visually
When you are faced with an absolute value equation or an inequality problem on the ACT, it might be helpful to see the graph before starting to solve the problem. Students sometimes start solving algebraically and might miss the fact there are two possible solutions. For example, there might be a problem like this:
Solve: |2x-5|=7
In this problem, you can graph |2x-5| in Y₁ and 7 in Y₂. Once you press the [graph] button, you’ll see there are clearly two solutions. One solution is at x = -1 and the other at x = 6.
8. Compute Fractions
Sometimes when under pressure, even fractions can start to look intimidating. If fractions are ever causing you some grief, use your calculator to simplify, add, subtract, multiply and divide fractions. You can also rewrite fractions as decimals. Press the [alpha] key then the [y=] key to pull up the fraction menu.
9. Solve Systems of Equations Graphically
You will be asked to solve systems of equations on the ACT math test. After you solve the problem algebraically, I suggest you check your solution graphically.
On the ACT, you might see a question like this:
Solve:
2x - 3y = -4
x + y = -1
- Press [2nd].
- Press [trace].
- Select [intersect] to find the intersection point.
10: Solve Systems of Linear Inequalities Graphically
There will also be problems on the ACT that will require you to solve systems of linear inequalities and find the points of intersection in the bounded region.
You can solve that problem algebraically and then use the Inequalities (Inequalz) app on your graphing calculator to check your solutions. This app even provides the intersection point of the lines. On the ACT, you might see a problem like this:
Solve:
x+2y ≤ 22
x−2y ≤ −2
x ≥ 2
Turn on the Inequalities feature by pressing the [app] key and selecting Inequalz. Then follow the steps in the video below to check your answer.
Test prep resources
Check out these test prep resources featuring additional blog posts, calculator tip videos and more. Explore the product tutorials for other useful tips. Remember to check your email frequently for any updates or test center cancellations — and best of luck!
