SAT Approved Calculator Guide & Tool
Your expert guide to the official policy on calculators that can be used on the SAT, plus a handy tool for common math problems.
SAT Math: Proportion Calculator
The SAT Math section often includes questions about ratios and proportions. This calculator helps you solve for a missing value ‘x’ in a proportion, based on the formula A / B = C / x.
The first value in the first ratio (A).
The second value in the first ratio (B).
The first value in the second ratio (C).
The Missing Value (x) is:
(4 * 5) / 2 = 10
Ratio Visualization
| If C changes by… | New Value of C | Resulting x |
|---|
What Calculators Can Be Used on the SAT?
Understanding the official SAT calculator policy is crucial for test day success. The College Board, which administers the SAT, has specific rules to ensure fairness. For the digital SAT, a graphing calculator is built directly into the testing application, which you can use for the entire Math section. However, you are also permitted to bring your own approved device.
Acceptable calculators include most graphing calculators, all scientific calculators, and four-function calculators (though the latter are not recommended due to their limited functionality). It is your responsibility to bring a working, battery-powered calculator. You cannot share calculators during the test.
The most significant rule is the prohibition of calculators with a Computer Algebra System (CAS). This was a key policy update, and models like the TI-Nspire CX II CAS are no longer permitted. Other prohibited features include QWERTY keyboards, internet access, cameras, or any device that needs to be plugged into an outlet. For more details, check out this guide on creating a study time planner.
The Proportion Formula and Explanation
Many problems on the SAT Math test involve ratios and proportions. A proportion is an equation stating that two ratios are equal. The calculator on this page solves a common proportion format:
A⁄B = C⁄x
To solve for the unknown value ‘x’, we use a method called cross-multiplication. This rearranges the formula to isolate ‘x’.
x = (B × C) / A
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| A | The numerator of the first ratio. | Unitless (or any consistent unit) | Any non-zero number |
| B | The denominator of the first ratio. | Unitless (or any consistent unit) | Any number |
| C | The numerator of the second ratio. | Unitless (or any consistent unit) | Any number |
| x | The unknown denominator of the second ratio. | Unitless (matches unit of B) | Calculated value |
A strong understanding of algebra is key to solving these problems. You may also want to use a GPA calculator to track your academic progress.
Practical Examples
Example 1: Map Scaling
A map key states that 2 inches represents 5 miles. If the distance between two cities on the map is 4 inches, how many miles apart are they?
- Inputs: A = 2 (inches), B = 5 (miles), C = 4 (inches)
- Calculation: x = (5 * 4) / 2
- Result: x = 10 miles. The cities are 10 miles apart.
Example 2: Recipe Adjustment
A recipe for 5 cookies requires 2 cups of flour. If you want to make 20 cookies, how many cups of flour do you need?
- Inputs: A = 5 (cookies), B = 2 (cups), C = 20 (cookies)
- Calculation: x = (2 * 20) / 5
- Result: x = 8 cups. You will need 8 cups of flour.
These types of questions are fundamental to the test. To see how your practice performance might translate, you could use an SAT score calculator.
How to Use This Proportion Calculator
This tool is designed to be simple and intuitive, helping you quickly solve for an unknown variable in a proportional relationship.
- Enter Value A: Input the numerator of the first ratio. This value cannot be zero.
- Enter Value B: Input the denominator of the first ratio.
- Enter Value C: Input the numerator of the second ratio.
- View the Result: The calculator automatically computes the value of ‘x’ and displays it in the results box. It also shows the intermediate calculation.
- Analyze the Chart & Table: The bar chart provides a visual comparison of the ratios, while the table shows how ‘x’ would change if ‘C’ were different.
Key Factors in Choosing an SAT Calculator
While the digital SAT provides a built-in Desmos calculator, many students prefer using a physical device they are familiar with. Here are six key factors to consider when choosing which of the calculators that can be used on the sat is right for you:
- 1. Familiarity: The best calculator is one you know how to use efficiently. Don’t bring a brand-new, complex graphing calculator to the test if you haven’t practiced with it.
- 2. Graphing vs. Scientific: A graphing calculator (like the TI-84 Plus) is powerful for visualizing functions, which can be a huge advantage. A scientific calculator is sufficient for most computations but lacks graphing capabilities.
- 3. Battery Life: Your calculator must be battery-operated. Ensure you have fresh batteries before test day, and consider bringing a spare set.
- 4. No CAS Functionality: As of recent policy changes, calculators with a Computer Algebra System (CAS) are banned. Double-check that your model is compliant.
- 5. Physical Condition: Make sure your calculator’s screen is easy to read and the buttons are responsive. A malfunctioning device can cause unnecessary stress.
- 6. Portability: You’ll have limited desk space. A very large or cumbersome calculator might be inconvenient.
Planning your college applications can be as important as your SAT score. A college acceptance calculator can help you assess your chances at different schools.
Frequently Asked Questions About the SAT Calculator Policy
1. Is a calculator required for the SAT?
No, a calculator is not required. All questions can be solved without one. However, it is highly recommended as it can save significant time and reduce calculation errors.
2. Can I use the calculator on my phone?
No. Mobile phones, smartwatches, laptops, or any device with wireless communication are strictly prohibited.
3. What happens if I bring a prohibited calculator?
Test center staff will not allow you to use it. You may have to take the math section without a calculator, which is a significant disadvantage.
4. Is the built-in digital SAT calculator good enough?
Yes, the built-in Desmos calculator is a powerful graphing tool that is sufficient for all problems on the test. Many students find it excellent, but if you are more comfortable with your own handheld calculator, you should bring it.
5. What is a Computer Algebra System (CAS) and why is it banned?
A CAS can perform symbolic manipulation, such as factoring expressions or solving equations algebraically. This is considered an unfair advantage, so calculators with this feature are not allowed.
6. Do I need to clear my calculator’s memory?
Yes, you must remove any stored programs or documents. Proctors may inspect your calculator. Keeping unauthorized information can lead to dismissal and score cancellation.
7. Can I use a calculator for the Reading and Writing section?
No. Calculators are only permitted during the Math section of the SAT. You must put it away during the other sections.
8. Which Texas Instruments (TI) calculators are allowed?
Most TI graphing calculators like the TI-83 Plus, TI-84 Plus, and the non-CAS TI-Nspire CX are allowed. However, models with “CAS” in the name are prohibited.