Fractions
Terms
Types of Fractions
Fraction
- A comparison between two quantities, a division problem. A number expressed in the form a/b such that b ¹ 0.Numerator - The top of a fraction. 3 Þ numerator
4 Þ denominator
Denominator - The bottom of a fraction.
Proper Fraction - A fraction where the numerator is less than the denominator, 3/4, 2/3, 5/16.
Improper Fraction - A fraction where the numerator is greater than or equal to the numerator, 4/3, 10/3, 5/5.
Mixed Numeral - A proper fraction and a whole number, 3 1/2, 4 4/7.
Equivalent Fraction - Two or more fractions which are equal.
Checking Equivalent Fractions - Equivalent fractions are checked by cross multiplying. The denominator of the first fraction is multiplied by the numerator of the second fraction. This product must equal the product of the second denominator the times the first numerator.
3 = 9 4 x 9 = 36 & 12 x 3 = 36, thus the fractions are equivalent
4 12
3 = 15 5 x 15 = 75 & 20 x 3 = 60, thus these are not equivalent
5 20
Generating Equivalent Fractions -
To generate an equivalent fraction the numerator and the denominator must be multiplied or divided by the same number.
3 x 2 = 6 3 x 3 = 9
4 x 2 = 8 4 x 3 = 12
Fractions
Simplifying Proper Fractions
Simplifying or Reducing a Proper Fraction
- Writing a fraction so the numerator and denominator have no factors in common.Techniques to simplify a proper fraction -
GCF Method -
Example - 30/36
GCF of 30 & 36 is 6; 30 ¸ 6 = 5 & 36 ¸ 6 = 6 5/6
Divisibility & Prime Number Chart -
Example - 30/36
30 & 36 are both divisible by two Þ 15/18
15 & 18 are both divisible by three Þ 5/6
5 is prime and does not divide evenly into 6, so 5/6 is the answer.
Fractions
Simplifying Improper Fractions
To simplify an improper fraction
-
Example - 20/6
1. 6Ö 20 3 r 2
2. 6Ö 20
18
2
3. Quotient = Whole Number
Remainder = numerator
Divisor = denominator
4. 3 2/6 = 3 1/3
Changing Mixed Numerals to Improper Fractions
To change a mixed numeral to an improper fraction
-
3 1/2 = 3 x2 = 6, 6 + 1 = 7, 7/2
Fractions
Comparing Fractions
Comparing Fractions
- Determining if the left fraction is greater than (>), less than (<) or equal to (=) the right fraction.To solve comparing fractions either use cross-multiplying or common denominator technique.
Cross-Multiplying -
4/5 ? 11/13 5x11 = 55 & 13x4 = 52 55 > 52, thus 4/5 <52 11/13
Common Denominators -
4/5 ? 11/13 common denominator = 65
new numerators = 52 & 55 52/65 & 55/65, thus 52/65 <55/65
Fractions
Changing Fractions to Decimals
Terminating Decimal
- A decimal which comes to a definite end.Repeating Decimal - A decimal which repeats in a specific pattern every time.
Changing fractions to decimals - Finding the decimal equivalent of a given fraction.
To solve -
.833.... .8
5/6 Þ 6Ö 5 Þ 6Ö 5.0000 4/5 Þ 5Ö 4 Þ 5Ö 4.00
4.8 4.0
20 0
18
20
18
2
Changing Decimals to Fractions
To solve
-Example -
.36 Þ place value is hundredths Þ 36/100 Þ 9/25
Fractions
Ordering Fractions
Ordering Fractions
- Determining the order of a group of fractions either smallest to largest or largest to smallest. Change the fractions to decimals, then compare the decimals.Smallest to largest -
5/6, 5/8, 3/4, 7/9 5/6 = .8333... 5/8 = .625 3/4 = .75 7/9 = .77...
.625 .75 .777.. .833.. Þ 5/8, 3/4, 7/9, 5/6