Lesson: Fractions: Clock Face
SWBAT model halves, thirds, fourths, sixths and twelfths on a clock face.
Materials Needed: scrap paper for DN, white board, dry erase markers, pencils, Example Chart Clock Faces, Clock Face Master (transparency for each student), slates (if desired), and IND Worksheet.
Vocabulary: whole (or ONE or unit), denominator, numerator, hexagon, trapezoid, rhombus, and triangle.
Do Now (2 -3 min): One the board the teacher writes the following: Why do you think there are 60 minutes in an hour?
Opening (2 -3 min): The teacher should state the objective, “Yesterday, we modeled fraction sums and differences with pattern blocks. Today, we are going to focus particular fractions. By the end of this lesson, you will be able to model halves, thirds, fourths, sixths and twelfths on a clock face.”
Direct Instruction (10 min): Teacher begins by briefly discussing the students’ ideas about why an hour is divided into 60 minutes. The teacher explains that ancient Babylonians based their number system on 60, and they used 60 because many numbers can evenly divide into it. The teacher asks the student to name whole numbers that can be divided with no remainder [1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60]. The teacher should explain that since 60 can be evenly divided by so many numbers, many fractions are easy to think about in a base-sixty number system.
The teacher should begin with an overhead of a clock face, and then model the following fractions on clock faces: ½; ¼; 1/3; 2/3; 1/6; 1/6; 5/6; 5/12. 1/6 should be modeled on two positions on the clock face. The Example Chart_Clock Face provides fractions in circle form and clock face masters, both small and large, to make transparencies or copies of. The teacher should use the circle fraction forms to correctly show the fractions on the clock face masters.
Guided Practice (10 min): The teacher should then pass out a large clock face transparency to each student. The students will be using dry erase markers on the transparency to represent specific fractions. If the teacher desires the students can tape the transparency to a slate board.
The teacher should begin, “Ok, now that we all have our materials, I want to explain what we will be doing. I am going to hold up a numerical fraction and I want you to represent it on your clock face. So, If I held up ¼ only ¼ of your clock face should be colored in. Watch as I show you ¼.” The teacher models by first drawing the lines of ¼ the clock face, and then lightly coloring within the lines.”
The teacher should use the following fractions for the students to represent.
1/6 (shown a different way)
Independent (10 min): The teacher then calls the students attention toward him/her before beginning IND work. The teacher passes out the IND Worksheet. The students are to hand in the IND Worksheet when finished.
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.
|Example Chart Clock Faces 3 Exemplar|
|Example Chart Clock Faces 2 Exemplar|
|Example Chart Clock Faces 1 Exemplar|
|Clock Face Master Exemplar|
|IND Clock Fractions Classwork|