When writing out the number 90, do you use ninty or ninety? If you use the latter, then you are right – the correct written form of the number 90 is always ninety. Curious as to why ninty is a common misspelling? Read on for the usage, meaning, and spelling of 90 and whether you should spell out this number or not.
What Is Ninety?
Ninety is the spelled-out version of the number 90, the whole number between 89 and 91. Usually used as an adjective, it indicates a quantity or a percentage. It’s also commonly used in geometry, as in right angles.
Sometimes, ninety can be a noun. An example would be as the subject of a sentence: “Ninety is the minimum score required for this program.”
Following are some examples of sentences using ninety correctly.
- Ninety citizens were in attendance for the school board meeting.
- Usually, the minimum average required for an A is ninety.
- After literally ninety attempts, the basketball player made the shot.
- Temperatures will be above ninety tomorrow.
- When driving, try to make ninety-degree turns so you don’t cut into other lanes.
Should 90 Be Spelled Out?
Sometimes, you see 90 spelled out, and other times, you see it in numerical form. What are the rules about this?
Spell Out 0-9
In most style guides, you should spell out 0-9 and use the numerical form for larger numbers. Why? Well, this is due to length; you would not want to write the entire word of 42,546,823.
Another rule is that you spell out a number when it begins a sentence. If you have a huge number and are a stickler for rules, just don’t begin your sentence with that number.
Numericals for Fractions and Decimals
You also use the numerical form for fractions and decimals because it’s simpler to use 90.5647 than it is to write “ninety and five hundred sixty-four thousandths.”
One Number Comes After Another
When one number comes after another, one should be written out while the other should be in numeral form.
For instance, “90 4-foot boards” is confusing to read. But if you write, “ninety 4-foot boards” or “90 four-foot boards,” it’s easier to understand.
Decades
Another time you write out a number is for decades. You should write “the nineties” for the 1990s, for example. On the other hand, you should use numbers for a specific year– 1991, for example.
Consistency
Finally, consider consistency. Say you’re writing a company email, and your company always to use numerical form. So, if you’re going to deviate from that, be consistent instead of switching back and forth.
Ninty or Ninety: Which Is Correct?
So is it ninty or ninety?
Let’s state this right away: ninty is not a real word. It’s not a regional or national variation in the way Americans and the British use theater/theatre and color/colour, respectively. Moreover, it’s not slang.
This might lead you to ask why we use forty instead of fourty or fifty instead of fivety, for example. Why don’t we use twoty and threety?
The answer is unsatisfying, but it’s the answer nonetheless: this is just how it is. English has a lot of weird rules, exceptions, and contradictions.
Trick to Remembering Which One to Use
So, how do you remember which to use? The best trick for remembering to use ninety and not ninty is simply to know that ninty isn’t a word and the incorrect spelling. However, here are some other tips:
- All words based on the number nine have the full spelling, and then whatever else goes with it. Examples: ninety, nineteen, nineteenth, ninetieth.
- Associate the word with an image of nine groups of 10. Nine times 10 is ninety.
- Use a grammar/spelling checker when you write.
Ninety vs Ninetieth: What’s the Difference?
In some instances, there can be confusion over whether to use ninety or ninetieth. Remember that ninety refers to an amount. Ninetieth, on the other hand, indicates a frequency or something’s position in a series. Consider the following two examples and think about how awkward they’d be with ninety instead:
- She finished ninetieth in the marathon.
- This feels like the ninetieth time you’ve asked that same question!
Final Thoughts
To recap, ninety is the correct spelling for the number 90. Ninty is a frequent misspelling, not an acceptable alternative even in text messages and essays. Knowing this makes it easy to know whether to write ninty or ninety. Beyond that, there are rules about when to use 90 and when you should spell it out. In most cases, though, clarity and consistency are more important than strict adherence to those rules.
