Negative Exponent in Calculator: Key Sequence
The calculator for this page is switched off while it is checked. The formula is below, and the worked example in the article shows how to use it by hand.
This guide shows you the exact button sequence to enter a negative exponent on a standard scientific calculator, and what to do on a phone or computer calculator app. You’ll learn the keystrokes for negative bases, negative exponents, and how to read the result correctly.
Formula
The formula you are entering is result = baseexponent.
Where:
- base — the number being multiplied by itself (unitless).
- exponent — the power to which the base is raised; a negative exponent means 1 divided by the base raised to the positive exponent.
- result — the computed value.
For a negative exponent, the rule is: a-n = 1 / (an). For example, 2-3 = 1/(2×2×2) = 1/8 = 0.125.
Worked Example
Using the default values: base = 2, exponent = -3.
- Enter the base: 2.
- Press the exponent key: ^ (or yx or xâ–¡).
- Enter the exponent as a negative number: press the (−) or (-) key, then 3. Do not use the subtraction key − (minus) for this.
- Press = or Enter.
The display shows 0.125 (or 1/8 in fraction mode). That matches the result from the calculator block above.
When to Use This
Use a negative exponent whenever you need to express a reciprocal: for example, converting units like meters per second (m·s-1), working with scientific notation (e.g., 1.5×10-3), or solving physics and chemistry problems that involve inverse-square laws.
How to Read the Result
A negative exponent does not make the result negative. It gives a value between 0 and 1 (if the base is positive). For instance, 2-3 = 0.125, not -8. If your base is negative and the exponent is an odd negative integer, the result is negative (e.g., (-2)-3 = -0.125). If the exponent is even, the result is positive.
Common Mistakes
- Using the minus key instead of the negative key. On most calculators, the subtraction key (−) is not the same as the negative sign key ((−) or (-)). Using minus can produce an error or an unexpected result.
- Forgetting parentheses around a negative base. If you type -2^3, many calculators interpret it as -(2^3) = -8, not (-2)^3 = -8 (same here, but different for even exponents: -2^2 = -4, while (-2)^2 = 4). Always use parentheses when the base is negative.
- Confusing the exponent sign with the base sign. For 2-3, only the exponent is negative. For (-2)-3, both are negative.
- Not pressing the exponent key before entering the exponent. If you just type 2 – 3, you are subtracting, not raising to a power.
Tips
- On a scientific calculator, look for a key labeled ^, yx, or xâ–¡. On some models, you press SHIFT or 2nd first.
- On a phone calculator, turn it sideways to get the scientific layout. On an iPhone, the exponent key is the ^ symbol. On Android, it may be ^ or yx.
- If your calculator has a fraction display mode, it may show the result as a fraction (e.g., 1/8) instead of a decimal. That is correct.
- For a quick check, remember that 10-3 = 0.001, and 10-2 = 0.01. This helps you verify the magnitude.
- When entering a negative exponent, press the negative sign before the number, not after. On most calculators, the negative sign is a small key near the bottom, often with parentheses around a minus sign.
Troubleshooting
- You get an error or “Syntax Error”. Check that you pressed the exponent key and not the subtraction key. Also make sure you have not left a parenthesis open.
- The result is negative when you expected positive. If your base is negative and the exponent is an even number, the result should be positive. If you got negative, you likely forgot parentheses. For example, -2^2 gives -4 on many calculators, but (-2)^2 gives 4.
- The result is a very small number like 0.000125. That is correct for a base larger than 1 and a negative exponent. For example, 2-10 = 0.0009765625. If you see scientific notation like 1.25e-4, that means 1.25×10-4 = 0.000125.
- You cannot find the negative sign key. On some calculators, the negative sign is the same as the minus key, but you must press it before typing the number, not after. On phone apps, look for a key that shows (−) or a small superscript minus.
- The calculator shows a fraction but you want a decimal. Press the S↔D (standard to decimal) key, or change the display mode from fraction to decimal in the settings.
Frequently Asked Questions
How do I enter a negative exponent on a TI-84?
Press the base number, then press the ^ key, then press the (-) key (located next to the Enter key), then type the exponent number, then press Enter. For example, 2 ^ (-) 3 Enter gives 0.125.
How do I put a negative exponent in a phone calculator?
Turn your phone sideways to access the scientific calculator. Tap the base, then the ^ or yx key, then the negative sign (often shown as (−)), then the exponent, then equals.
Why does my calculator give a negative number for a negative exponent?
It should not, unless the base is negative and the exponent is an odd integer. For a positive base, a negative exponent always yields a positive decimal between 0 and 1. If you see a negative result, check that you did not accidentally type a minus sign instead of the exponent key.
What is the difference between the minus key and the negative key?
The minus key (−) is for subtraction, like 5 − 3. The negative sign key ((−) or (-)) is used to indicate a negative number, like −3. Using the wrong one can cause errors, especially when entering exponents.
Can I use a negative exponent with a negative base?
Yes. For example, (-2)-3 = 1 / ((-2)^3) = 1 / (-8) = -0.125. Use parentheses around the negative base to ensure the calculator applies the exponent to the whole negative number.
How do I enter a negative exponent in Google’s online calculator?
Type the base, then the caret symbol ^, then parentheses around the negative exponent. For example, type 2^(-3) and press Enter. Google will return 0.125.
Related
Formula used
in base | Base | - | 2 | 0 in exp | Exponent | - | -3 | 0 out result | Result | - | base ^ exp | 4
Each line is one input (in, sel, list) or one result (out: label, unit, formula, decimals). How the calculators work
Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.