Can You Use a Calculator on the GMAT?
If you’re preparing for the GMAT and wondering whether you can use a calculator, you’re not alone. The GMAT tests quantitative skills, but calculator usage isn’t as straightforward as you might think. Understanding when a calculator is allowed—and more importantly, how to excel without one—can significantly impact your performance on test day. So, let’s break down the rules and share some strategies to help you thrive without relying on a calculator.
Are Calculators Allowed in GMAT?
The short answer: it depends on the section, so here’s a breakdown of the relevant sections and whether calculators are permitted:
- Quantitative Section: You cannot use a calculator on the Quantitative section of the GMAT. This section tests problem-solving, critical thinking, and logical reasoning using secondary-level math. Rather than performing complex calculations, the focus is on finding efficient solution paths.
- Data Insights Section: In contrast, an on-screen calculator is provided for the Data Insights section. This calculator includes basic functions such as addition, subtraction, multiplication, division, and square roots, along with memory functions. However, over-reliance on this tool can slow you down, so it’s essential to develop strong mental math skills.
The restriction on calculators in the Quant section might feel daunting, but it’s important to remember that the GMAT isn’t designed to test your arithmetic skills. Instead, it emphasizes logic, estimation, and clever problem-solving approaches
If You Are Doing Math, You’re Doing It Wrong
At Apex, we believe that if you’re focused on crunching numbers during the GMAT, you’re on the wrong track. As Mike Diamond, Director of Curriculum Development at Apex, says, “If you’re doing math, you’re doing something wrong.” This doesn’t mean math isn’t important; it means that the GMAT requires you to apply math intelligently, rather than just compute numbers
Because of this, all the computational work on the GMAT should be simple and easy to do with decent mental math. It’s the less efficient solution paths that benefit from the use of a calculator, so ironically, knowing how to solve a problem using a calculator can get in the way of your seeing a faster solution path when preparing for this exam.
The GMAT encourages you to find alternative ways to solve problems that avoid tedious calculations. By seeing the big picture, applying estimation, or eliminating unreasonable answer choices using logical reasoning, you can often arrive at the correct answer without needing any calculation at all.
Let’s look at a typical problem:
Example:
You are asked the following:
The value of 20! Would end with how many zeros?
Of course, you could use your paper to multiply 20*19*….*1 to get an insanely huge number. Even if you had a calculator, it wouldn’t be practical to solve the problem in this way. However, by recognizing that a “0” is the result of having both a prime factor of 2 and a prime factor of 5, you can then search for how many 2s and 5s there are in the string of 20! And rapidly get the answer. Try it for yourself before looking at the answer at the bottom of this article.
This highlights the importance of thinking logically and strategically rather than focusing on computation.
How to Survive the GMAT Without a Calculator
Mastering the GMAT without a calculator might seem challenging, but with the right mental math strategies, you can navigate the test efficiently. Below are some key mental math techniques and tips to make the Quant section less daunting for the beginner.
Mental Math Basics
Before diving into specific techniques, it’s essential to review some basic mental math rules:
- Divisibility by 2: Numbers with an even last digit (e.g., 576) are divisible by 2.
- Divisibility by 3: If the sum of the digits is divisible by 3 (e.g., 3,465 → 3 + 4 + 6 + 5 = 18), the number itself is divisible by 3. The same rule works for 9.
- Divisibility by 5: Numbers ending in 0 or 5 are divisible by 5.
- Divisibility by 10: Numbers ending in 0 are divisible by 10.
There are many more divisibility rules, but these foundational rules help you quickly assess numbers and simplify many calculations in your head
Advanced Mental Math Tricks
Once you’ve mastered the basics, you can apply these advanced mental math tricks to save time on the GMAT:
Avoid Division
Try to avoid long division unless absolutely necessary. Instead, break numbers down into simpler components. For example, if you need to divide 192 by 6, first simplify by factoring the numbers into smaller parts, like 192 ÷ 2 = 96 and then 96 ÷ 3 = 32.
How to Divide/Multiply by 5
Instead of directly dividing or multiplying by 5, think of it as multiplying by 10 and then halving the result. For instance, to calculate 62 × 5, you can first calculate 62 × 10 = 620, then divide by 2 to get 310. Similarly, dividing by 5 can be achieved by multiplying by 2 and then dividing by 10.
Substitute 9 with 10
Whenever you encounter the number 9, it’s often easier to think of it as 10 minus 1. For example, to calculate 46 × 9, you can express it as 46 × (10 – 1), which simplifies to 460 – 46 = 414. This method saves time and reduces calculation errors.
Finding the Square of a Double-Digit Number
Squaring two-digit numbers can be simplified by breaking them into components and FOILing (Firsts, Outers, Inners, Lasts). For instance, to square 22:
(20 + 2)² = (20 + 2)*(20 + 2)
20*20 = 400
+ 20*2 = 40
+ 2*20 = 40
+ 2*2 = 4
400 + 40 + 40 + 4 = 484
By breaking the number down into smaller, easier to process chunks, you simplify the calculation and reduce potential errors
Why Not to Use a Calculator on Data Insights
While you do have a calculator for Data Insights, it’s important to realize that it’s largely there as a timing trap. In fact, DI problems almost never require calculation, and when they do there’s always a smooth workaround. With time already being a huge factor for DI (that’s how they get you!), don’t fall for the temptation to begin using the clunky on-screen calculator when attacking the problem in a different manner will always yield a faster result.
The Answer to The Problem
In the strong of 20!, there are four factors of 5 (from the 5, 10, 15, and 20). Since a zero is created by the pair of a 5 and a 2, we can see that we’ll have four 0s at the end of 20!. Notice that since there are always more 2s than 5s, you don’t even need to count the 2s. Pretty straightforward once you think about it a little bit.
Learn More Tricks to Ace the GMAT with Apex
Mastering mental math is an essential skill for the GMAT, but it’s just one piece of the puzzle. At Apex, we specialize in helping you develop personalized strategies that go beyond just teaching shortcuts—we focus on building your problem-solving and critical thinking skills. Our one-on-one, personalized tutoring ensures a tailored approach that addresses your unique strengths and areas for improvement. With expert guidance, and customized study plans, we help you develop the strategies needed to excel on the GMAT and in business school.
Ready to take your GMAT prep to the next level? Schedule a free call with a senior instructor and learn how you can master the GMAT—calculator or not!