Rule for Writing Numbers

In January 22 post, I have highlighted few points showing the differences between American and British writing. While working on a document, I was checking the rules for writing number. I got some useful information, which I would like to share with my writer friends. 

Although, you must be aware of these rules, but this will be helpful for some beginners.

Below are the rule for writing numbers-

1. Spell out the numbers 0-9 i.e. smaller than 10
2. Never start a sentence with a numeral. For e.g. - 
• Ten years ago, I was staying in hostel. (Correct)
• 10 years ago, I was staying in hostel. (Incorrect)
3. Spell out centuries and decades
4. Use digits for expressing percentage and recipe ingredient (measurement/quantity)
• She has achieved 84% in high school examination.
• Add 2 cup of water in the wok
5. Use numerals for expressing measurement or calculations
• 10 cm x 5 cm (Correct)
• Ten cm x Five cm (Incorrect)
6. Spell out ordinal numbers 
• First, Second, Third (Correct)
• 1st, 2nd, 3rd (Incorrect)
7. Make the sentence consistence when expressing numbers 
• John ranks second among eight students.  (Correct)
• John ranks second among 8 students. (Incorrect)
• Shopkeeper gave me 8 chocolates not 10. (Correct)
• Shopkeeper gave me eight chocolates not 10.  (Incorrect)
8. Spell out the numbers to express simple fraction and also use hyphen
• One-third of the land has been sold out.
9. Use numerals for mixed fraction
• Lolly got 9 1/2 marks in Mathematics.
• Note: If mixed fraction digit starts a sentence, it would be expressed in words.
• Nine and one-half marks is the highest in the maths class test.
10. Spell out the rounded numbers