In a fraction, the denominator tells us how many parts the whole is divided into, and the numerator tells us how many of those parts we're dealing with.
- We can read this fraction as four-fifths, four over five, or four divided by five.
The number above the bar is called the numerator, and the number below the bar is called the denominator.
Proper fraction: numerator is less than the denominator. (Ex. 1/2, 2/5)
Improper fraction: numerator is greater than or equal to denominator. (Ex. 3/2, 8/5)
Mixed number: whole number and a fraction. (Ex. 2 3/5, 4 6/7)
Equivalent fractions: fractions that represent the same number. (Ex. 1/3=2/6=3/9)
Reciprocal: the multiplicative inverse of a number. For a fraction, it's obtained by "turning the fraction over". (Ex. 3/7 and 7/3)
Examples:
1/2 a half
1/2 a half
11/16 eleven sixteenth
1/3 a/one third
4 2/5 four and two fifths
1/4 a/one quarter
1/16 a/one sixteenth
236/407 two hundred thirty six over four hundred and seven
0.3 nought point three
0.527 nought point three seven five
8.9 eight point nine
1.5 one and a half
2.5 two and a half
- With fractions below 1, we use of before nouns. Half is a little bit different.
three quarters of an houreight tenth of a milea fifth of students
- For decimals below 1, you can use of or a plural noun.
nought point seven of a mile = nought point seven miles
- Fractions and decimals over 1 are normally followed by plural nouns.
One and a half hours2.7 millimeters
- To express amounts and measurements, use singular verbs with fractions and decimals.
3.6 kilometer is about 2 miles.
- But to express numbers of people or things, use plural verbs.
Half the students are tired.A fifth of the tickets have been sold.
- We can use a or one. One is more formal.
a hundred (less formal)one hundred (more formal)
- A can only be used at the beginning of a number.
a/one hundredthree thousands one hundred , three thousands a hundred
