3 To ADD or SUBTRACT fractions with like denominators: Add or subtract the numerators only. Keep the denominators the same.Simplify (in lowest term) the fraction, if possible.(hint: Find the GCF - What’s the largest number that goes into the numerator and denominator equally?)If you end up with an improper fraction , change it to a mixed number. Why?(hint: Divide the denominator into the numerator)
5 6 4 3 4 Adding mixed numbers with like denominators. 2 1/8 + 2 5/8 1/8 If James has two and one eighth pizzas and Jane has two and five eighths pizzas, how many pizza’s do they have together.2 1/8/81/8/86/8Step 1: Add the Fractions2+2=4Step 2: Add the whole numbers468Step 3: Combine the whole number and the fraction.43Step 4: Simplify if possible
8 + List the multiples of both denominators. 4: 4, 8, 12, 16, 20 6: 6, 12, 18, 24, 30Find the least common multiple (LCM).Write new fractions with the LCM as the new denominator.1 14 6+1 ?4 126 12=+
9 Find the factor you multiply by to get from your original denominator to your new denominator or divide the new denominator by the old .Use that same factor, and multiply it by your original numerator to get a new numerator.3 ?4 121 ?6 12=+12 ÷ 4 = 3 x 312 ÷ 6 = 2 x 11112
10 Adding Mixed Numbers Process: Separate the whole number parts from the fraction parts.Find common denominators for the fractions and then add them.Add the whole numbers together.Simplify.
11 BorrowingWhen the top numerator is smaller than the bottom numerator, you MUST BORROW!Take one whole from the top whole number.Make that one borrowed into a fraction having the same denominator as your common denominator.Add that numerator to the new numerator.This is now your newer numerator that you will use to subtract from.3103105211- 810+ 1013 1010=11=410488==101092
12 Don’t forget to SIMPLIFY! Let’s Try These93+45674-123593-456Don’t forget to SIMPLIFY!
14 Multiply Fractions: Just Follow These Easy Steps! Multiply the numerators and write down the answer as your new numerator.Multiply the denominators and write down the answer as your new denominator.Simplify.
15 Example3261x==93664This fraction can be reduced. Divide the numerator and denominator by the GCF, which is 6.
16 Multiplying by a Whole Number Turn your whole number into a fraction by placing a 1 as the denominator.If your answer is improper, divide the bottom into the top.45x201=8016
17 Simplifying FactorsBefore you multiply, you can make the problem simpler.You can find the GCF of any numerator and denominator.Find a factor that equally divides the top number and bottom number.Divide and rewrite the problem.
18 Example 1In the second fraction, 8 and 16 have a GCF of 8.151458x=8 ÷ 8 = 1 and 16 ÷ 8 = 27162Now, multiply with the simpler numbers. 5 x 1 = 5 and 7 x 2 = 14.
19 Or Cross-cancelIn the first fraction, the numerator and the denominator of the second fraction have a GCF of 4.145x16=In the second fraction, the numerator and the denominator of the first fraction have a GCF of 5.16 ÷ 4 = 4 and 5 ÷ 5 =1Now, multiply across. 1 x 1 = 1 and 1x 4 = 4.
20 To Multiply Mixed Numbers: Change any mixed numbers to improper fractions.Simplify factors if possible.Multiply numerators by numerators and denominators by denominators.Simplify and/or change improper fractions back into mixed numbers.
27 ADDING and SUBTRACTING FRACTIONS Find common denominatorFind new numerator.Add numeratorsKeep denominators the sameAdd whole numbersSimplify if possibleFind common denominatorFind new numeratorTop numerator must be larger than bottom.Borrow from whole number if not.Subtract numeratorsSimplify if possible+++++
28 Multiplying and Dividing Fractions Change mixed fraction to improper fractionSimplify fractions or cross-cancelMultiply across (numerators and denominatorsSimplify if possibleChange mixed fraction to improper fractionChange (÷) to (×)Flip the second fractionSimplify fractions or cross-cancelMultiply across (numerators then denominatorsSimplify if possiblex x x x x÷ ÷ ÷ ÷ ÷
29 ClassworkTry This Interactive Game to Help You Review Operations with FractionsBUG SPLATHOMEWORK TIME!!!Adding, Subtracting, Multiplying, and Dividing Fractions (Handout)