Lesson 15
Write Times
Warm-up: True or False: Close To 30 (10 minutes)
Narrative
The purpose of this True or False is to elicit understandings students have for the meaning of the equal sign. Students may reason about whether the expressions on either side of the equal sign are the same without finding their values by using the properties of operations or their understanding of place value (MP7).
Launch
- Display one statement.
- “Give me a signal when you know whether the statement is true and can explain how you know.”
- 1 minute: quiet think time
Activity
- Share and record answers and strategies.
- Repeat with each statement.
Student Facing
Decide if each statement is true or false.
Be prepared to explain your reasoning.
- \(30 = 30\)
- \(10 + 15 = 15 + 10\)
- \(10 + 10 + 10 = 3\)
Student Response
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Activity Synthesis
- “How can you explain your answer without finding the value of the sum on both sides of the equal sign?”
Activity 1: Count the Minutes (10 minutes)
Narrative
The purpose of this activity is to connect 30 minutes to telling the time at the half hour. Students learn that there are 30 minutes in half an hour by counting the intervals around an analog clock that represent the minutes. Some students may count by ones, but others may notice a pattern and count by 5 or 10 (MP7). Although some students may point out that 30 is half of 60, this relationship is beyond grade-level expectations.
Launch
- Groups of 2
- Display the clock in the student book.
- “Each of the little lines around the clock represents a minute.”
Activity
- “Start at the top mark, at the 12, and count half of the clock. How many minutes is that?"
- “Circle where you stop, then check with your partner to see if you agree.”
- 2 minutes: independent work time
- 1 minute: partner discussion
- Monitor for students to circle the mark below 6.
Student Facing
Start at 12.
Count the minutes around the clock until you get to half the clock.
Circle where you stop.
Student Response
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Activity Synthesis
- “How did you keep track of your count?” (I counted by ones. I marked each time I got to ten, and did that 3 times.)
- Display clock showing 2:30.
- “What time does this clock show?” (Half past 2)
- “We just learned that if we count the number of minutes halfway around the clock, we count 30 minutes. When the minute hand has gone half way around the clock, the time is half past. We can write the time as 2:30. The 2 represents the hour and the 30 represent the minutes.”
- Display clock showing 4:30.
- “How would we write the time?” (4:30)
Activity 2: All the Time in the World (25 minutes)
Narrative
The purpose of this activity is for students to write time to the hour and half hour based on clocks with one or both hands.
MLR8 Discussion Supports. Synthesis: For each observation that is shared, invite students to turn to a partner and restate what they heard using precise mathematical language.
Advances: Listening, Speaking
Advances: Listening, Speaking
Engagement: Develop Effort and Persistence. Chunk this task into more manageable parts. Check in with students to provide feedback and encouragement after each chunk.
Supports accessibility for: Attention, Social-Emotional Functioning
Supports accessibility for: Attention, Social-Emotional Functioning
Required Materials
Materials to Gather
Required Preparation
- Each student needs their Half Past Clock Cards from a previous lesson.
Launch
- Groups of 2
- Give students their Half Past Clock Cards.
- “Write the times on the new clock cards that show half past.”
- 2 minutes: independent work time
Activity
- “What time is shown on each clock? Work on the questions by yourself and then compare your work with your partner’s.”
- 7 minutes: independent work time
- 3 minutes: partner discussion
Student Facing
- For each clock, write the time.
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- For each clock, draw the minute hand and write the time.
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This clock only has a minute hand.
What time could it be?
Draw an hour hand and write the time.
If you have time: What other times can you show on the clock?
Student Response
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Activity Synthesis
- Display the clock with the hour hand pointing between the 4 and the 5.
- “How can the hour hand help you know if the minute hand should point to the 12 or the 6?” (If the hour hand points to a number, then the minute hand points to 12. If the hour hand points halfway between two hours then the minute hand points to the 6.)
- “How did you know to put :30 in the written time?” (When the minute hand is on the 6, 30 minutes have gone by so it is _:00.)
- Display the problem where students draw in the hour hand and write the time.
- “How did you know where to put the hour hand?” (The hour hand has to point between 2 numbers because it is ‘half past’.)
Lesson Synthesis
Lesson Synthesis
Display a clock showing 3:30 and a clock where the hands are reversed (the hour hand points to 6 and the minute hand points to 3):
Cool-down: Time in Half-Hours and Hours (5 minutes)
Cool-Down
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