1. Adding and Subtracting Fractions
With Unlike Denominators
Kate Hall

2. Vocabulary Numerator –The top number in a fraction
Denominator – The bottom number in a fraction.
Multiple - the product of two numbers
Least common Denominator – the lowest multiple that the two denominators share in common.
Divisible – a number that is divided by another number that does not leave a remainder.
Simplify – means that the numerator and denominator can be divided by the same number to make the fraction smaller.

3. Adding and Subtracting with Unlike Denominators _ 4 5 4 5 8 10 12 15
Multiply
Denominators 16 20 20 25

4. Using Fraction Bars
Take the fraction you are adding or subtracting on your fraction strips.
Line them up with the rest of your fraction strips and see which fraction you are lined up with.
For example 1/4 + 1/3 = 7/12
1/3
1/4 1 12 1 12 1 12 1 12 1 12 1 12

5. Adding and Subtracting with Unlike Denominators
Solve: 4 5

6. Adding and Subtracting with Unlike Denominators
Solve: 8 4

7. Adding and Subtracting with Unlike Denominators
Solve: 1 3

8. Partner Work
Choose your favorite method and solve these five problems.
/4 + 1/6
/ /6
/ /4
/6 - 2/12
/ /5