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Real Life Fractions. http://www.ed.gov/pubs/EarlyMath/8.jpg. When do we use fractions?. Cooking Measurement Telling time Money. What is a fraction?. Fractions show part of something. Such as pieces of a pizza, part of an hour, half a pound, a quarter of an dollar.
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Real Life Fractions http://www.ed.gov/pubs/EarlyMath/8.jpg
When do we use fractions? • Cooking • Measurement • Telling time • Money
What is a fraction? • Fractions show part of something. Such as pieces of a pizza, part of an hour, half a pound, a quarter of an dollar. • The top of the fraction is the numerator. It tells the pieces. • The bottom of the fraction is the denominator. It tells how many make up a whole.
What the fraction looks like. Numerator 1 Part Denominator 2 Whole/All parts
Equivalent Fractions Sometimes we can write a fraction more than one way. If we have 4 out of 6 slices of cake left we can write our fraction two ways, because 4/6 = 2/3. 4/6 is shaded and also 2/3 is shaded. http://www.mathleague.com/help/fractions/fractions.htm#whatisafraction
Equivalent Fractions Look to see if the numerator and denominator have a like factor. If they do, we can simplify the fraction. Examples: 3 and 9 have like factors, so 3/9 = 1/3.
Adding Fractions When we combine units the denominators need to bee the same. Meaning, when we add fractions, we have to have like denominators. 2 +3 = 53+ 6= 9 7 7 7 11 11 11
Common Denominators • If you are not given like denominators, you have to find the least common denominator. • Take your denominators, and factor them out. • Then, match up any common denominators. Pull one factor for each match. For example 2x2=4 and 2x3=6, so pull out one 2 since there is a 2 in each.
Common Denominators • Next, account for the numbers not matched up. So for 4 and 6, we would account for the 2 and 3 that did not match up. • We would multiply all the numbers together. Meaning the 2 and 3, with the number we took out earlier, which was a 2. • So from 2 x 2 =4 and 2 x 3 = 6, our denominator would be 2x2x3=12.
Find the common denominator when given these two fractions. • 1+ 2= ? 3 9 ? Remember your denominators are 3 and 9.
If you put 9 you are right! 3 x 1 = 3 and 3 x 3= 9 One 3 matches up, so take it out. The rest does not, so take the remaining 3 and 1 out. 3 x 3 x 1 = 9
How to change into equivalent fractions. Once you have found your common denominator, you need to find the equivalent fractions. 1 = 3 Because we need 9 as our denominator, 3 9 we multiply 3 x 3 to get 9. What ever we multiply the denominator by, we do the same to the numerator.
If our denominator has to be 12, try to find the numerator. 3 = ? 4 12
If you said 9 you are correct! 3 = 9 4 12 Because 4 x 3 = 12, you have to multiply the top by 3 also. 3 x 3 = 9
Once you have like denominators you can add. Solve 3+ 2= ? 9 9 ?
Exactly! 3+ 2= 5 9 9 9 Try this one next: 2 + 1 = 3 5 Remember you need to find like denominators.
Did you get: 2 + 1 = 13 3 5 15 Why? Your denominator has to be 15, because 3 and 5 have no like factors, so multiply 3 x 5 = 15. 10 + 3= 13 15 15 15
Congratulations! You are on your way to mastering fractions.
Works Cited Picture on Page 1 • http://www.ed.gov/pubs/EarlyMath/8.jpg Picture on Page 5 • http://www.mathleague.com/help/fractions/fractions.htm#whatisafraction All other pictures clip art.