Adding Fractions with Unlike Denominators
1/4 + 2/3 =
11/12
4/5 - 1/3 =
7/15
1/2 and 3/5
LCD: 10
If the denominators are the same for two fractions, do we have to find the least common denominator (LCD)?
No, we can add or subtract the fractions as is.
What is the division expression for 3/4
3 ÷ 4
4/9 + 1/6 =
*write your answer in simplest form
11/18
4/3 - 2/7 =
23/21 or 1 2/21
5/12 and 2/9
LCD: 36
What is the first thing you do when you are adding or subtracting fractions with unlike denominators?
Find the least common denominator (LCD) for all of the fractions.
What is the division expression for 45/6
45 ÷ 6
DAILY DOUBLE!! (2x points)
3/4 + 1/9 =
31/36
3/4 - 1/9 =
23/36
1/20 and 4/8
LCD: 40
DAILY DOUBLE!! (Points x2)
Add AND subtract 3/4 and 1/5
15/20 and 4/20
Addition = 19/20
Subtraction= 11/20
Write the fraction for this division expression: 6 ÷ 4
HINT: turn the division expression into a fraction, and convert to a mixed number!
6 ÷ 4 = 6/4 = 1 1/2
1/2 + 1/3 =
5/6
6/7 - 1/2 =
5/14
9/12, 5/8
LCD: 24
What are 2 ways you can get two fractions with unlike denominators to have the same denominator?
1) Find the least common denominator (LCD)
2) Multiply the two denominators by one another
DAILY DOUBLE!! (x2 points)
Write the fraction for this division expression: 16 ÷ 7
HINT: turn the division expression into a fraction, and convert to a mixed number!
16 ÷ 7 = 16/7 = 2 2/7
1/4 + 3/7 =
19/28
9/10 - 1/4 =
*Write your answer in simplest form
13/20
1/4, 2/3, and 3/9
LCD: 36
When answering a fraction problem, your answer should always be in it's most ___________ form
Reduced or simplified
Write the fraction for this division expression: 36 ÷ 5
HINT: turn the division expression into a fraction, and convert to a mixed number!
36 ÷ 5 = 36/5 = 7 1/5