Welcome to adding & subtracting fractions basics By: Mr. Garcia Click here for next slide

Menu Adding and Subtracting Fractions with a common denominator. Simplifying Fractions Use your mouse and click on the plus (+) or minus (-) sign to reach the desired section. Adding and Subtracting Fractions with a different denominators. Changing Improper Fractions to Mixed Numbers. Finding a common denominator. End Show

Adding and Subtracting Fractions Step 1: Check your fractions to see if they have a common (same) denominator (bottom number). Click here for next slide.

Step 2: If both denominators are the same, then add the two numerators (top number) together. Adding and Subtracting Fractions Click here for next slide.

Step 3: After adding the two numerators together, that answer will be your new numerator. Your denominator will stay the same. Adding and Subtracting Fractions Click here for next slide.

Final Step: You always have to check if you can simplify your answer. Adding and Subtracting Fractions Click here for main menu.

Step 1: Check your fractions to see if they have a common (same) denominator (bottom number). Adding and Subtracting Fractions with Uncommon Denominators Click here for next slide.

Step 2: Because these fractions do not have the same denominator you must find a common denominator for them before you can add or subtract. Adding and Subtracting Fractions with Uncommon Denominators Click here for next slide.

One strategy you can use, to find a common denominator, is to list the multiples of the denominators until you find one common to both numbers x 1= 8 8 x 2=168 x 3=248 x 4=328 x 5=40 8 x 6= x 1 = 1010 x 2=2010 x 3=30 10 x 4= 40 Adding and Subtracting Fractions with Uncommon Denominators Click here for next slide.

Change both fractions to new fractions with this common denominator. To do this, multiply the denominator by the factor that will equal the common denominator. Adding and Subtracting Fractions with Uncommon Denominators Click here for next slide.

Whatever changes you make to the denominator, you must make the same to the numerator. Adding and Subtracting Fractions with Uncommon Denominators Click here for next slide.

Now add the two numerators together and the denominator will stay the same. Adding and Subtracting Fractions with Uncommon Denominators Click here for next slide.

Finally you need to simplify your answer. In this example the answer is improper therefore to simplify it, we need to change it to a mixed number. After you change it to a mixed number you still need to check if you can simplify the fraction. If you forgot how to change an improper fraction to a mixed number go to that section of the presentation. Adding and Subtracting Fractions with Uncommon Denominators Click here for main menu.

Because these fractions do not have the same denominator you must find a common denominator for them before you can add or subtract. Finding a Common Denominator Click here for next slide.

One strategy you can use, to find a common denominator, is to list the multiples of the denominators until you find one common to both numbers x 1= 8 8 x 2=168 x 3=248 x 4=328 x 5=40 8 x 6= x 1 = 1010 x 2=2010 x 3=30 10 x 4= 40 Finding a Common Denominator Click here for next slide.

Change both fractions to new fractions with this common denominator. To do this, multiply the denominator by the factor that will equal the common denominator. Finding a Common Denominator Click here for next slide.

Whatever changes you make to the denominator, you must make the same to the numerator. Finding a Common Denominator That is how you find a common denominator. Now add and simplify. Click here for next slide.

A second strategy to finding a common denominator is to is to multiply the two fractions by the opposite denominator. Finding a Common Denominator Click here for next slide.

You will multiply the first denominator by 8 and the second denominator by 10. Finding a Common Denominator Click here for next slide.

Whatever changes you make to the denominator, you must make the same to the numerator. Finding a Common Denominator That is how you find a common denominator. Now add and simplify. Click here for main menu.

Simplifying Fractions When you add, subtract, multiply, or divide fractions you always have to check if you can simplify your final answer. To simplify your final answer you have to find a common factor that you can divide the numerator and denominator by. Click here for next slide.

Simplifying Fractions To find the common factor you should list all the factors of the numerator and denominator. Click here for next slide.

Simplifying Fractions All of the factors that are the same in both lists are common factors. Click here for next slide.

Simplifying Fractions You can divide the fraction by any one of these common factors. To get the fraction in simplest form you should divide by the greatest common factor. In this example the greatest common factor is 8. Therefore divide by 8. Click here for next slide.

Simplifying Fractions After you divide by 8 the answer you get is your answer in simplest form. Click here for main menu.

Changing Improper Fractions to Mixed Numbers Click here for next slide.

Changing Improper Fractions to Mixed Numbers The first thing you need to do is divide the numerator by the denominator. Click here for next slide.

Changing Improper Fractions to Mixed Numbers Seven goes into 12, 1 time. Click here for next slide.

Changing Improper Fractions to Mixed Numbers You use the Quotient, Divisor, & Remainder to make your mixed number Quotient Divisor Remainder Click here for next slide.

Changing Improper Fractions to Mixed Numbers The quotient becomes the whole number. The Divisor was the denominator and remains the denominator. The remainder is your numerator. Quotient Divisor Remainder 5 Numerator Whole Number Denominator Click here for next slide.

Changing Improper Fractions to Mixed Numbers The final thing you need to check is can the fraction be simplified. In this example it can not therefore you are finished. Click here for main menu.