The plus or minus symbol is a small but powerful symbol used in math, science, and everyday writing.
Many people wonder which form is correct and how to use it properly. In this guide, we will explain the meaning, correct usage, common mistakes, and tips to remember it.
By the end, you’ll never confuse this symbol again.
Which One Is Correct – Plus or Minus Symbol?
The correct form is “±”.
Many people mistakenly write “+-” or “+/-,” but these are technically informal or shortcuts. The ± symbol is universally recognized in mathematics and scientific notation.
- Why “+-” is wrong: It is just a combination of characters and doesn’t hold the official meaning.
- Why “±” is right: It represents two possible values, one positive and one negative, in a single, concise symbol.
Meaning of “±”
The ± symbol means “plus or minus”, indicating that a number or value could be either positive or negative. It is commonly used in mathematics, science, and measurements.
Simple explanation: When you see 5 ± 2, it means 5 + 2 or 5 – 2.
Examples:
- The answer is 10 ± 3, meaning it could be 13 or 7.
- The temperature today is 20°C ± 2°C.
- The medication dose is 50mg ± 5mg.
- The measurement reads 100cm ± 1cm.
- The test results were 80% ± 10%.
Meaning of “+-” or “+/-”
The “+-” or “+/-” is often used informally in typing or texting.
Definition: It is a way to type “plus or minus” when the proper symbol isn’t available.
When it is used:
- Online forums
- Word processors without symbol support
- Quick notes or casual communication
Examples:
- The margin of error is 5+-2.
- You can type 100+/-5 if the ± symbol isn’t on your keyboard.
- My height is 170+/-2 cm.
- Use 50+/-10mg for rough estimates.
- The result is 30+/-3 points.
While understandable, “+-” is not recommended for formal writing or scientific documentation.
Why Do People Confuse ± and +-?
Confusion arises due to:
- Spelling similarity: Both symbols use plus and minus signs.
- Pronunciation: People say “plus or minus” for both.
- Typing mistakes: “+-” is easier to type on keyboards without the ± symbol.
Just Plus or Minus Symbol – Is It Correct?
Using plus or minus symbol alone is correct, but context matters.
- In math and science, always prefer “±”.
- In casual writing, some use +- but it is informal.
- Avoid replacing ± in textbooks, papers, or reports.
Easy Trick to Remember the Difference
Think of it like a shortcut:
- ± = official, recognized, correct
- +- = informal, quick typing
Memory tip: The line through the symbol (±) shows it combines plus and minus into one. If it looks like two separate characters, it’s probably +-, which is less professional.
Related Phrases with Plus or Minus Symbol
- In no case: Never use “+-” in formal math.
- In any case: ± works for all correct scientific measurements.
- In that case: Use ± to show uncertainty or range.
Examples:
- The reading is 50 ± 5, in any case, the result is accurate.
- In no case should you write 50+-5 in your report.
- The device tolerates 10 ± 1 volts; in that case, ± ensures precision.
Common Misspellings (Table Format)
| Correct | Incorrect |
| ± | +- |
| ± | +/- |
| definitely | definatly |
| necessary | neccessary |
| separate | seperate |
| measurement | measurment |
| accommodate | acommodate |
| occurrence | occurence |
| recommend | reccommend |
| explanation | explenation |
| argument | arguement |
| existence | existance |
| guarantee | guarentee |
| convenience | conveniance |
| license | licence |
Frequently Asked Questions
Is +- ever correct?
It’s okay in informal typing, but ± is preferred for math and science.
Is it one word or two?
“Plus or minus symbol” is written as four words.
Can I use it in formal writing?
Always use ± in formal or scientific writing.
What does ± mean?
It means a number could be positive or negative, showing a range or margin of error.
Why do people type +/-?
Because it’s easy on keyboards when ± isn’t available.
Conclusion
The plus or minus symbol is a simple yet important symbol used worldwide in mathematics, science, and measurements. Always use ± for correct notation and avoid shortcuts like +- in formal writing. Understanding its meaning and proper usage ensures clarity, accuracy, and professionalism in all your work.
Michael Reed is a passionate language enthusiast who has spent over a decade exploring the nuances of English grammar. Writing has always been his way of sharing knowledge, simplifying complex rules, and helping readers express themselves clearly. He believes that good grammar is the bridge between ideas and understanding, making communication powerful and precise. When he isn’t writing, Michael enjoys reading classic literature, experimenting with creative writing, and mentoring young writers. His goal is to make grammar accessible, enjoyable, and practical for everyone. Michael’s dedication to language learning has inspired thousands to embrace the beauty of words every day.
Books by Michael Reed:
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Mastering Grammar Made Simple
-
The Essential Guide to English Writing
