The usage and rules of numbers in grammar are very simple.
The main rules for writing numbers are the following:
1.
When writing single digit numbers, write the number in word form.
For example:
I counted four puppies
under the mother.
Here, since the number four is only
one digit, it is written in word form.
2.
For numbers over nine, use the numeral form.
Consider the following example:
There were about 20
policemen at the scene of the crime.
In this example, since the number
20 is over 9, 20 is written out in numeral form.
You may be wondering why in the
above sentence, the number nine was written in numeral form. The next rule addresses
that point.
3.
Write the same form of numbers in the same sentence, no matter how big
or small they are.
For example:
My 12 parrots ate 3
pounds of food in total.
My twelve parrots ate three
pounds of food in total.
In the first sentence, 12 is in
numeral form because it is more than nine. There is a three in the same
sentence; however, because of the above rule, the three must also be written in
numeral form to stay consistent throughout the sentence.
The same example can be written also
as the second sentence above. Just remember to be consistent throughout a
sentence.
4.
When writing simple, well-known fractions (one-third, two-thirds,
one-half, three-fourths, etc.), write them out in word form with hyphens in
between.
Consider the following example:
Kelly must have been very hungry;
she ate three-fourths of the entire jumbo pizza!
Here, since three-fourths is a simple,
well-known fraction, it is written out in word form.
5.
When writing large numbers, the simplest way is the best way. Round
numbers, such as multiples of a million or a thousand, are usually written in
word form. Complex numbers, such as 572,384,583, however, are written in
numeral form.
For example:
Tom made a profit of $1,015 from
his lemonade stand last year.
Here, the number is written in
numeral form. However, remember to be consistent within the same sentence.
For example:
She earned $102,834,100 from her
new company’s sales, but she lost 1,000,000 when she made the wrong bet in the
stock market.
Here, even though it would be
easier to write “one million” instead of the numeral form, it has to be in
numeral form since 102,834,100 is also in numeral form.
6.
Usually write decimals in numeral form.
For example:
The food weighed 7.83 pounds on
the grocery store scale.
Here, the decimal “7.83” is written
out in numeral form.
7.
When two numbers are written next to each other, write them in different
forms to properly distinguish them from each other. As for which number to
write out, some people write out the smaller one; however, there is no
definite rule for this.
Consider the following sentence:
He ate 8 two-ounce mini-burgers at
his favorite restaurant.
In this example, the numbers eight
and two are right next to each other, so one is written in numeral form while
the other is written in word form.