This presentation is the property of its rightful owner.
1 / 13

Fractions PowerPoint PPT Presentation

Fractions. By: Lisa Fogle. What are fractions?. They are part of a whole. Comes from the Latin word fractio meaning to break or break apart. Have numerator and a denominator They are written as a over b or a/b, the a is the numerator and b is the denominator.

Related searches for Fractions

Fractions

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Fractions

By: Lisa Fogle

What are fractions?

• They are part of a whole.

• Comes from the Latin word fractio meaning to break or break apart.

• Have numerator and a denominator

• They are written as a over b or a/b, the a is the numerator and b is the denominator.

• There will always be a fraction between two fractions, this is called density of fractions.

Models for Fractions

• Part-to Whole concept

• Is used to show part of a whole object.

• The fraction a/b, a is the part of the whole and b is the whole.

• The example to the right is 2/8. Having the whole as eight and the two as part of the whole reduces to ¼.

Models continued

• Division Concept

• Is also called the measurement or sharing concept.

• Trying to divide a whole with bars by a certain number.

• The example to the right shows that 2/5 equals 4/10.

Models continued

• Ratio concept

• It’s used to compare one amount to another.

• Example is a girl’s height is ½ of her mother’s height.

• Can use rods to compare the weights or size or amount.

Equality of Fraction

• Shows how fractions are equal and how they represent the same amount.

• With this you can use simplification of fractions by finding a common factor between the two numbers. This will help reduce the fraction to it’s simplest form.

• An example is, 8/20 = 2/5 because 2 times 4 is 8 and 5 times 4 is 20 giving you 8/20.

Common Denominators

• Show that two fractions can have the same denominator to determine their Inequality.

• An inequality is to determine which fraction are greater then or less than of each other.

• Example, a/b<c/d if and only if ad<bc

• Or if a/b>c/d if and only if ad>bc.

Mixed Numbers

Are when improper fractions are written as a whole number and a fraction combined.

An example would be 2 1/3.

Improper Fractions

They are fraction with a numerator greater than or equal to the denominator.

An example would be 7/4 or 4/4.

Different types of Fractions

• Concepts to use

• Combining two sets of objects

• Example, 1/3+1/5 would be 5/15+3/15 because you need to find the common denominator of the two. The answer would be 8/15.

• 1/3+1/3, can be added across since they have a common denominator giving you the answer of 2/3.

• For mixed numbers first add the fractions then the whole numbers in order to get the answer.

• Provides visual example on how to add fractions

- Is a good source to see how fractions are added.

Subtracting Fractions

• Can use the take-away concept, missing addend or the partitioning.

• Fraction bars or number lines can be used to display models.

• Finding the common denominator can be beneficial when you subtract two fraction that have different denominators.

• http://cne.gmu.edu/modules/dau/algebra/fractions/frac3_frm.html

• This site is good for adding and subtracting fractions

Multiplying Fractions

• Repeated addition is used when you multiply a whole number by a fraction.

• Example, 4*3/4 shows that the product is 3. This answer was solved my cross multiplying. Having the fours cancel each other.

• Fraction times a fraction by dividing a rectangle by the denominator, then shade in the region where the fractions take place. The answer will be the area that was shaded twice.

• Example, a/b x c/d= ac/bd

Dividing Fractions

• Can be represented by using the repeated subtraction concept.

• Want to use the terms “How many times,” does one number go into the other.

• Example, a/b divided by c/d=a/b x d/c=ad/bc.

• Fraction bars are one of the models that represents division.

Fraction operations websites

• http://www.visualfractions.com/

• Gives example of adding, subtracting, multiplying and dividing fractions by using concrete examples.

• http://www.aaamath.com/B/fra.htm

• Provides various concepts of fractions and allows the students to practice the operations of fractions.