Lesson: Fractions: Wholes and Collections
SWBAT find fractions of wholes, when the whole is a collection of objects.
Materials Needed: scrap paper for DN, white board, dry erase markers, pencils, penny manipulatives, straws/yarn, chart paper, and IND Worksheet (2 versions for high and low group)
Vocabulary: whole (or ONE or unit), denominator, numerator, and collection.
Do Now (2 -3 min): One the board the teacher writes the following: Take 20 pennies. What is ½ of 20? The students should at least have a drawing of the 20 pennies on the board, or have manipulatives to complete this Do Now.
Opening (2 -3 min): Teacher quickly reviews the answer to the Do Now and has students share their thinking or strategy for finding the answer. Then the teacher should state the objective, “Yesterday, we identified fractions on a number line. Today, we going to focus on finding fractions when our whole is a collection of items. By the end of this lesson, you will be find fractions of wholes, when the whole is a collection of objects.”
Direct Instruction (10 min): Teacher begin by partnering up the students. “Today, we are going to start by working in partner. Please quietly find your math buddy.” The teacher hands each pair 24 pennies and to divide them into 3 equal groups. The teacher should emphasize that the whole is 24 pennies, or 24 cents, not 1 penny. Stress the importance of identifying the whole in any problem involving fractions.
The teacher should model the strategy of drawing 3 groups of 8 separated by a straw or yarn to represent the WHOLE, 24 pennies. The teacher should say, “I am trying to make 3 fair shares, so I have 8 in each of them.” The teacher should then ask the following questions:
• How much is the whole? 
• The pennies in each group represent what fraction of all the pennies? [1/3]
• How many pennies are in each group (or share)? 
• What if I gave 2 of these groups to Mary. What fraction of the whole would Mary have [2/3].
• How much is 2/3 of 24 pennies? [16 pennies or 16 cents]
The teacher should then review the concept to reinforce learning. The teacher draws 24 pennies on the board and says the following: “One way to find 2/3 of 24 is to first find 1/3 of 24, which is …. Since 1/3 of 24 is 8, 2/3 of 24 must be twice as much …or .
Guided Practice (10 min): The teacher writes the following on a chart or the board:
How much is ¼ of 32?__________ 2/4 of 32?___________ ¾ of 32?___________
How much is 1/5 of 30?________ 2/5 of 30?___________ 4/5 of 30?__________
How much is 2/3 of 27?________ 5/6 of 30____________
The teacher works through each of the first 4 problems with the students. For the other 4 problems the teacher should split students into groups of 3 or 4 and have them solve the problems together and then report back to the class. The level of difficulty for each problem differs so it can easily be differentiated.
Independent (10 min): The teacher then calls the students attention toward him/her before beginning IND Work. The students are handed IND Worksheet.
Closing (2-3 min): Teacher calls the attention of the students back toward the front of the class to quickly review the answers to the Independent Practice worksheet/ ask what we learned about.
|IND parts of a whole differentiated Classwork|
|IND parts of a whole Classwork|