Adding and Subtracting Fractions, Adding and Subtracting Mixed Numbers, Like Denominators

When adding and subtracting fractions, what needs to be the same?

• the numerator

• the denominator

• nothing

• everything

When adding fractions with like denominators, the denominators....

• stay the same

• are added together

When adding or subtracting fractions with unlike denominators, what is the first step?

• Add the numerators

• Add the denominators

• Find a common denominator

How can you find a common denominator?

• Add the denominators together

• Pick your favorite number

• Find a common multiple for the two denominators

1 11/12 + 2 5/12

• 4 1/3

• 3 4/12

• 4 16/12

• 1    5/12
• 3     11/24
• 3    11/12
• 3    1/2

What is the sum of these fractions in lowest terms?

• 5/12

• 5/24

• 6/12

• 6/144

Which equation represents the shaded parts of the model?

• 5/5 + 5/5 = 10/5

• 3/5 + 4/5 = 5/5

• 1/5 + 2/5 = 3/5

• 1/5 + 1/5 = 2/5

What is the sum of these fractions in lowest terms?

• 7/18

• 7/9

• 12/9

• 12/81