When every second counts on the ACT® Math section, knowing what to punch into your calculator — and when — can be the difference between a great score and a frustrating one.

For students balancing school, sports, and test prep, calculator strategy is one of the fastest ways to gain points. At The Krupnick Approach, our expert ACT tutors teach students how to use their calculators efficiently — so they can save time, avoid mistakes, and boost their scores quickly.

Whether you’re testing this spring or next fall, these calculator tips will help you work faster and smarter on test day.

Why Calculator Strategy Matters

The ACT allows calculators, but not every question requires one. In fact, overusing your calculator can actually slow you down. The key is learning when to reach for it — and when not to.

Effective calculator use lets you:

Double-check arithmetic quickly
Simplify complex algebraic steps
Graph functions and visualize solutions
Avoid small calculation errors that cost easy points

However, relying on it for simple math wastes precious time. Students who know how to strike the right balance tend to score significantly higher.

The Best Calculators for the ACT

Before you can use your calculator efficiently, make sure it’s ACT-approved. Popular options include:

TI-84 Plus CE, the gold standard for most students
TI-83 Plus, simple, reliable, easy to use
TI-Nspire CX, non-CAS version
Casio fx-9750GII

Double-check that your model isn’t a CAS, or Computer Algebra System, version, since those are banned.

In addition, always practice with the exact calculator you’ll use on test day. Familiarity reduces hesitation and helps you move faster when the clock is ticking.

What to Punch In — and When

1. Fractions and Decimals

When you’re comparing values, use your calculator’s fraction and decimal conversion features. For example, to compare 5/6 and 0.8, simply enter 5 ÷ 6 to get a decimal value and decide instantly. This saves time on proportion and ratio questions.

2. Graphing Linear and Quadratic Equations

The ACT often includes questions about line intersections or parabola behavior. Instead of solving algebraically under pressure, you can:

Enter each equation in Y= mode
Use GRAPH and 2nd → CALC → intersect to find the solution quickly

This trick works best when both equations are already in y= form.

3. Substitution and Verification

If you’re unsure about an algebraic solution, plug your answer choices back into the equation. Use parentheses carefully and press ENTER after each step. This method eliminates careless sign errors and helps you check your work efficiently.

4. Percent Change and Growth Questions

Percent change problems can be calculator traps. To save time, use this direct formula:

Percent Change = (New – Old) / Old × 100

Entering it once correctly — and storing it if needed — prevents mistakes under time pressure.

5. Trig and Geometry Shortcuts

For trigonometry questions, memorize the mode settings your calculator should be in:

The ACT uses degree mode, not radians.
Check before the test: MODE → DEGREE → ENTER.
Then, functions like sin(30) or cos(45) give the correct values instantly.

6. Use Memory and Variables

Most ACT-level calculators let you store values using the STO key. This feature is extremely helpful when working with multi-step problems. Instead of retyping numbers, store them as A, B, or C and recall them with one button.

This small time-saver adds up over the 60-minute math section.

Common Calculator Mistakes to Avoid

Even the best calculator can’t fix poor strategy. To use it wisely, avoid these common pitfalls:

Entering answers before checking signs or parentheses
Switching modes accidentally, such as radians vs. degrees
Overusing the calculator for simple arithmetic
Ignoring estimation — always double-check if an answer makes sense logically

Ultimately, your calculator is a tool, not a crutch. Used well, it speeds you up and keeps you accurate. Used carelessly, it can cause easy mistakes.

How The Krupnick Approach Teaches Calculator Strategy

At The Krupnick Approach, we go beyond test prep — we teach strategy. Our one-on-one ACT Math tutoring helps Chicago students learn:

How to recognize calculator-eligible problems instantly
Which steps to do by hand versus by device
How to eliminate wrong answers through smart estimation
How to build speed and accuracy through timed drills

Moreover, we personalize every lesson based on your calculator model and math strengths. This way, you’ll enter test day with a clear, confident plan — and the muscle memory to execute it fast.

Local Expertise, Real Results

Our ACT prep students routinely see score increases of 3–6 points after targeted tutoring. Many credit calculator strategy as one of the simplest yet most powerful ways to boost math scores quickly.

FAQs

Do I need a graphing calculator to succeed on the ACT?

Not necessarily. A scientific calculator is often enough, but graphing models make some algebra and geometry questions much faster.

Can I bring extra batteries?

Yes, you can bring spare batteries as long as they’re loose and not connected to any device.

How soon before the test should I start practicing calculator use?

Ideally, begin at least three weeks before test day to build comfort and efficiency.

Get a Smarter Score — Fast

Even a great math student can lose points without the right calculator strategy. With expert guidance from The Krupnick Approach, you’ll learn exactly what to punch in — and when — to maximize every minute of your ACT Math section.

Get started today with a complimentary consultation from our experts.

Get started today with a complimentary consultation from our experts.