Adding and Subtracting Fractions


Lesson 1: Prime Factorization
Main Idea: every positive integer (except the number 1) can be represented as a product of one or more prime numbers in exactly one way, disregarding the order of the factors. Standard (s): 5.OA.A.2.1 Express a whole number in the range 250 as a product of its prime factors. For example, find the prime factors of 24 and express 24 as 2 x 2 x 2 x 3. Related Links: Fruit Shoot Primes and Composite 
Lesson 2: Finding Prime Factors
Main Idea:
Standard (s): Express a whole number in the range 250 as a product of its prime factors. For example, find the prime factors of 24 and express 24 as 2 x 2 x 2 x 3.
Related Links:
Factor Trees
Main Idea:
Standard (s): Express a whole number in the range 250 as a product of its prime factors. For example, find the prime factors of 24 and express 24 as 2 x 2 x 2 x 3.
Related Links:
Factor Trees
Lesson 3 : Problem Solving: Writing to Explain
Main Idea: Students explain how to estimate fractional amounts of objects. They learn that mathematical explanations can be given using words, pictures, numbers, or symbols. They also learn that a good explanation should be correct, simple, complete, and easy to understand.
Standard (s): 5.NF.A.2 Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2.
Related Links:
Main Idea: Students explain how to estimate fractional amounts of objects. They learn that mathematical explanations can be given using words, pictures, numbers, or symbols. They also learn that a good explanation should be correct, simple, complete, and easy to understand.
Standard (s): 5.NF.A.2 Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2.
Related Links:
Lesson 4 : Estimating Sums and Differences of Fractions
Main Idea: Students use a number line to estimate sums and differences of fractions. They learn that fraction sums and differences can be estimated by replacing fractions with the closest half or whole.
Standard (s): 5.NF.A.2 Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2.
Related Links:
Shape Shoot
Main Idea: Students use a number line to estimate sums and differences of fractions. They learn that fraction sums and differences can be estimated by replacing fractions with the closest half or whole.
Standard (s): 5.NF.A.2 Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2.
Related Links:
Shape Shoot
Lesson 5 : Adding Fractions with Unlike Denominators
Main Idea: Students use models and computational procedures to add fractions with unlike denominators. They learn that to add with unlike denominators, you can change to an equivalent calculation with like denominators.
Standard (s): 5.NF.A.1 Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12 . (In general, a/b + c/d = (ad + bc/bd) .
Related Links:
Pacman
Main Idea: Students use models and computational procedures to add fractions with unlike denominators. They learn that to add with unlike denominators, you can change to an equivalent calculation with like denominators.
Standard (s): 5.NF.A.1 Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12 . (In general, a/b + c/d = (ad + bc/bd) .
Related Links:
Pacman
Lesson 6 : Subtracting Factions with Unlike Denominators
Main Idea: Students use models and computational procedures to subtract fractions with unlike denominators. They learn that to subtract with unlike denominators, you can change to an equivalent calculation with like denominators.
Standard (s): 5.NF.A.1 Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12 . (In general, a/b + c/d = (ad + bc/bd) .
Related Links:
Fruit Shoot Subtraction
Main Idea: Students use models and computational procedures to subtract fractions with unlike denominators. They learn that to subtract with unlike denominators, you can change to an equivalent calculation with like denominators.
Standard (s): 5.NF.A.1 Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12 . (In general, a/b + c/d = (ad + bc/bd) .
Related Links:
Fruit Shoot Subtraction
Lesson 7 : More Adding and Subtracting Fractions
Main Idea: Students solve problems involving addition and subtraction of fractions. They learn that fractions with unlike denominators can be added or subtracted by replacing fractions with equivalent fractions with like denominators. The product of the denominators of two fractions is a common denominator of both.
Standard (s): 5.NF.A.1 Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12 . (In general, a/b + c/d = (ad + bc/bd) .
Related Links:
Fruit Shoot Subtraction
Main Idea: Students solve problems involving addition and subtraction of fractions. They learn that fractions with unlike denominators can be added or subtracted by replacing fractions with equivalent fractions with like denominators. The product of the denominators of two fractions is a common denominator of both.
Standard (s): 5.NF.A.1 Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12 . (In general, a/b + c/d = (ad + bc/bd) .
Related Links:
Fruit Shoot Subtraction
Lesson 8: Problem Solving Draw a Picture and Write an Equation
Main Idea: Students draw pictures and write equations to solve problems. They learn how information in a problem can often be shown using a diagram and used to solve the problem. They also learn that some problems can be solved by writing and completing a number sentence or equation.
Standard (s): 5.NF.A.2 Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2.
Related Links:
The Adventures of Mrs. Meatball
Fraction War
Main Idea: Students draw pictures and write equations to solve problems. They learn how information in a problem can often be shown using a diagram and used to solve the problem. They also learn that some problems can be solved by writing and completing a number sentence or equation.
Standard (s): 5.NF.A.2 Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2.
Related Links:
The Adventures of Mrs. Meatball
Fraction War