Fractional Parts of an Hour (Day 2)

4 teachers like this lesson
Print Lesson

Objective

SWBAT manipulate fraction pieces that represent different parts of an hour to create combinations that equal 1 hour in all.

Big Idea

Time and fractions are related!

Basic Facts with Fives

8 minutes

If your students are fluent with basic facts then you can skip this section.  Few of my third graders are and they also have an easier time when the first addend is the large one.  In other words, they don't apply the commutative property well.  This Addition Practice Basic Five Minutes practice gives students practice adding the five minute increments found in an hour (15, 25, 35 and so on) and then also with adding 1, 2, 3, or 4 minutes on to a 5 minute increment.

Review of Activity Directions

6 minutes

Quickly review the instructions for the models they began to build yesterday. Show them a few additional examples of possible models.  fraction time 1fraction time 2fraction time 3fraction time 4 .  Point out where the supplies are located (extra piece sheets, scissors to cut them out, glue bottles or glue sticks).  I suggest that you have them layout their models first, with the copied equations underneath, and then ask you to check them before they glue.

Remind them to keep the two systems (time and fractions) separate when they are writing their equations.  In other words:

yes:  1/4 + 1/4 + 1/3 + 1/12 + 1/12 = 1

yes:  15 + 15 + 20 + 5 + 5 = 60

no:  1/4 + 15 + 1/3 + 1/12 + 5 = 60

Activity

42 minutes

Students continue to layout fractional parts of an hour in models to represent 60 minutes/ 1 whole. They write the equations under each model.  If they layout a model that doesn't fit over the 60 minute template (link) but it does equal 1 whole/60 minutes, accept it. After all, an hour isn't really a rectangle!

As you circulate, have students articulate what they are doing, what relationships they see, what they have discovered, what they might still have a question about, and what the purpose of the activity is.

Can you tell me what you are learning? Why are you learning this?

How do you know your work is (good, correct, proficient)?

What can you tell me about....?

Can you explain what .... means?

What examples show....?

Can you prove....?

How would you show....?

Do you have any questions about....?

This is an excellent time for intervention and extension.  The students who need more reinforcement of the basics can build models with only like fractions.  (All thirds, all fourths, and so on).  The children who need extension can be challenged to recreate a model they've already built in an additional combination of fractions.  For example, a student who has built this model of an hour:

1/4 + 1/2 + 1/4  (15 min. + 30 min. + 15 min)

can be asked how else she could make the fourths, and if she could make each of them a different way.  Then she might create this:

(1/6 + 1/12) + 1/2 + (1/6 + 1/12) = (10 + 5) + 30 + 10 + 5 = 60 minutes

Wrap Up

6 minutes

Clean up:

Any students who haven't finished their model may want to put the pieces they know they will need in a separate bag.  The rest of the materials can be collected in a general bag and then resorted later for future use.  I suggest having a spot cleared so that their drawings can be laid out to dry.  Someone will most certainly have been overzealous with the glue, and this will prevent papers from sticking to each other! Have students begin to write a 3-4 sentence response to this question:

What have you learned about time and fractions in the past 2 days?  What is something that surprised you or that you found interesting?  Why?  What did you like/dislike about the activity?  Why?  What do you still have questions about?

3rd graders are still very literal.  I emphasize that they don't have to answer ALL these questions. They may write only about what they learned, for example.  I circulate to make sure they can all get started, and model precise language.

They will finish this at home for homework.

Here is an example of a student response that shows an understanding of the idea that it takes fewer large chunks of time (20 minutes/ thirds) to "cover" an hour than it does smaller chunks of time.  The precision of language is still developing. Fractional Parts Hour Exit Ticket MC

Here is another student whose takeaway seems to be the math facts that multiply to equal sixty.  He does express that they are in minutes.  I talked to this student further to see if I could get them to elaborate upon their explanation, and they did state that they were using various quantities of time as represented by different size fractions.  No, they did not use those words!  Fractional Parts Hour Exit Ticket Example 2