Add & Subtract Fractions

ESSENTIAL UNDERSTANDING:

• Fractions can be added & subtracted when the wholes are same size & the fractional parts (denominators) are the same. 

• Fractions with different denominators are called unlike fractions

• Fractions with different denominators can be added & subtracted by replacing each fraction with an equivalent fraction expressed with a like denominator. 

• A fraction with a numerator larger than the denominator can be expressed as a mixed number or a fraction greater than one; both are correct representations. 

• Expressing a mixed number as a fraction, e.g., 2 3/5 = 13/5, may be useful when solving a fraction problem.

• Benchmark fractions may be used to estimate & to check whether answers are reasonable.

• Common denominators are needed to add and subtract fractions with unlike denominators.

• Multiples may be used to find common denominators.

• An equation can be used to describe a mathematical situation involving fractions.

• There is usually more than one way to describe & solve a mathematical situation involving fractions

• Benchmark fractions may be used to estimate & to check whether answers are reasonable. 

Student I Can Statements:

• I can add fractions with unlike denominators by replacing the given fraction with equivalent fractions.

• I can subtract fraction with unlike denominators by replacing the given fraction with equivalent fractions. 

• I can solve real world problems involving the addition & subtraction of fraction s with unlike denominators. 

• I can solve world problems involving addition of fractions with like/unlike denominators by using a visual fraction model.

• I can solve world problems involving subtraction of fractions with like/unlike denominators by using a visual fraction model.

• I can use benchmark fractions & general number sense to determine the reasonableness of my answer.