Common Denominators
What is an equivalent fraction for 1/3? (Hint: multiply the numerator and denominator by the same number.)
2/6
3/9
4/12
5/15
4/6 + 1/6=
5/6
4/8 -2/8=
2/8
1/5 of 40=
8
What is 2/3 of 3/4? (Draw a picture if necessary.)
6/12
Write the equivalent fractions for 2/3 and 1/6, so they have common denominators.
4/6 and 1/6
3/8 + 2/8=
5/8
5/6 - 3/6=
2/6
3/5 of 40=
24
What is 2/5 of 2/4? (Draw a picture if necessary.)
4/20 OR 1/5
Write the equivalent fractions for 2/4 and 3/8, so they have common denominators.
4/8 and 3/8
2/3 + 3/6=
7/6 or 1 1/6
2/4 - 3/8=
4/8 - 3/8 = 1/8
30 x 3/10=
9
Describe the strategy for finding a common denominator.
-I found the least common multiple of each of the denominators.
-I multiplied the two denominators together.
Write the equivalent fractions for 3/5 and 1/2, so they have common denominators.
6/10 and 5/10
3/4 + 5/6=
9/12 + 10/12= 19/12= 1 7/12
4/6 - 2/4=
8/12 - 6/12 = 2/12
12 x 3/6=
6
Draw the picture of 3/6 x 1/3.
See teacher model.
Write the equivalent fractions for 3/4 and 2/3, so they have common denominators.
9/12 and 8/12
8 2/3 + 3 1/5=
8 10/15 + 3 3/15= 11 13/15
6 3/4 - 3 2/3=
6 9/12 - 3 8/12= 3 1/12
4/5 x 3/10=
12/50
20 x 3/5
Will the product or answer be larger or smaller than 20? How do you know?
The product will be smaller than 20 because I multiplied by a number less than 1.