Sandra needs 2 3/4 cups of flour for one kind of cookie and 3 3/8 cups for another kind. How much would she need for both kinds?
2 6/8 + 3 3/8 = 5 9/8 = 6 1/8
To find out how much flour Sandra would need for both kinds of cookies, you need to add the amounts of flour needed for each kind.
First, let's convert the mixed numbers to improper fractions for easier calculations.
2 3/4 can be written as 11/4, and 3 3/8 can be written as 27/8.
Now, we will add the two fractions:
11/4 + 27/8.
To add fractions with different denominators, we need to find a common denominator. In this case, the least common multiple of 4 and 8 is 8.
Once we have a common denominator, we can add the numerators:
11/4 + 27/8 = (11*2)/(4*2) + 27/8 = 22/8 + 27/8.
Now, we simply add the numerators:
22/8 + 27/8 = (22 + 27)/8 = 49/8.
The sum of the two fractions is 49/8.
However, we usually express mixed numbers for measurements. To convert this improper fraction to a mixed number, we divide the numerator by the denominator:
49 ÷ 8 = 6 with a remainder of 1.
So, Sandra would need 6 whole cups and 1/8 (or 1/8 cup) of flour for both kinds of cookies.