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Adding and Subtracting Like Fractions. Adding and Subtracting Fractions. Combining Like Units : . To be “like”: the items must share the same characteristics. 2 inches, 3 meters, 5 hours, 2 minutes. Can any of these numbers be added together?. No, the units of measure aren’t the same.
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Adding and Subtracting Fractions Combining Like Units: To be “like”: the items must share the same characteristics 2 inches, 3 meters, 5 hours, 2 minutes Can any of these numbers be added together? No, the units of measure aren’t the same. Ex. 2 feet + 6 inches We need to convert the units of measure so they are the same.
Adding and Subtracting Fractions Just how units of measure must be the same, so must fractions be like. Ex. 2 inches + 7 inches = 9 inches 2 fourths + 7 fourths = 9 fourths Like Fractions: if two or more fractions have the same denominator, then the fractions are “LIKE”.
Adding and Subtracting Fractions Combining Like Fractions: Adding Fractions: + = Subtracting Fractions: - = a c a+c b b b a c a-c b b b
Adding and Subtracting Fractions Combining Like Fractions: Adding Fractions: + = Subtracting Fractions: - = a c a+c b b b a c a-c b b b YTI#1:Perform the indicated operation. 7 1 15 15 10 5 13 13 a) + b) - YTI#2:Perform the indicated operation. 8 2 20 20 18 3 25 25 a) + b) -
Adding and Subtracting Fractions Combining Like Fractions: Adding Fractions: + = Subtracting Fractions: - = a c a+c b b b a c a-c b b b YTI#3:Perform the indicated operation. -14 4 25 25 -17 13 40 40 a) + b) - YTI#4:Perform the indicated operation. 4 8 9 9 -17 11 30 30 a) x + x b) b2 - b2
Adding and Subtracting Fractions Adding Mixed Numbers with like denominators: YTI#5:Perform the indicated operation. 4 9 2 9 3 7 2 7 a) 1 c) 15 +3 +23
Adding and Subtracting Fractions YTI#6:Perform the indicated operation. 2 7 5 7 3 4 2 4 a) 1 c) 39 +3 +16
Adding and Subtracting Fractions Subtracting Mixed Numbers with like denominators: YTI#8:Perform the indicated operation. 3 7 2 7 3 8 1 8 5 12 a) 4 b) 7 c) 17 -1 -1 -13
Adding and Subtracting Fractions Let’s look at: 2 9 7 9 a) 5 - 2 We need to make the fractional part of the first number > second number.
Adding and Subtracting Fractions YTI#10:Perform the indicated operation. 3 7 5 7 1 12 5 12 a) 4 c) 10 -1 -3
Adding and Subtracting Fractions YTI#11:Shira is almost finished putting in the Guzmans’ new hardwood floor and has only to put baseboard around three short blank wall spaces. The measures of the three spaces are 5 inches, 7 inches, and 4 inches. What is the total length of these three measures? 5 9 16 16 7 16
Adding and Subtracting Fractions YTI#12: Natalie made two custom bookcases. One bookcase is 38¼ inches high and the other is 32¾ inches high. What is the difference in the heights of the two bookcases?