# Lesson 14

Half of the Clock

## Warm-up: Number Talk: Work with 30 (10 minutes)

### Narrative

The purpose of this Number Talk is to elicit strategies and understandings students have for adding within 100.

### Launch

• Display one expression.
• “Give me a signal when you have an answer and can explain how you got it.”
• 1 minute: quiet think time

### Activity

• Record answers and strategies.
• Keep expressions and work displayed.
• Repeat with each expression.

### Student Facing

Find the value of each expression mentally.

• $$30 + 10$$
• $$30 + 15$$
• $$30 + 30$$
• $$30 + 35$$

### Student Response

Teachers with a valid work email address can click here to register or sign in for free access to Student Response.

### Activity Synthesis

• “Who can restate _______ 's reasoning in a different way?”
• “Did anyone have the same strategy but would explain it differently?”

## Activity 1: Put Times in Order (15 minutes)

### Narrative

The purpose of this activity is for students to see that the hour hand doesn’t always point directly at a number on the clock. Students see that the hour hand can be between two hours. The end of the activity synthesis provides an opportunity for formative assessment of students’ understanding of the language of “half past” which they will continue developing in the next activities.

### Required Materials

Materials to Gather

Materials to Copy

• Clock Cards Half Past

### Required Preparation

• Each student needs their clock cards from the previous lesson.

### Launch

• Groups of 2
• Give each student their clock cards from the previous lesson, a copy of the blackline master, and scissors.
• Display the image from the student book.
• “What do you notice? What do you wonder?”
• 1 minute: quiet think time
• 1 minute: partner discussion
• Share and record responses.

### Activity

• “Cut out your new cards and put them with your other clock cards. Then organize all the cards in a way that makes sense to you. Be ready to explain how you organized the cards.”
• 5 minutes: independent work time

### Student Facing

What do you notice?
What do you wonder?

### Student Response

Teachers with a valid work email address can click here to register or sign in for free access to Student Response.

### Activity Synthesis

• Display cards showing 7:00, 7:30, 8:00
• “_______ put their clocks in this order. Why do you think they did that?” (The hour hand is moving from the 7 to the 8 and on the middle clock, it’s in between.)
• “On the second clock, the hour hand is halfway between the 7 and the 8, so we can name the time as ‘half past 7.’”
• “Hold up the card that shows half past 3. Hold up the card that shows half past 12.”

## Activity 2: Half Past What? (10 minutes)

### Narrative

The purpose of this activity is for students to identify whether a clock is showing a time that’s half past or o’clock. Students use the position of the hour hand to determine the time.
MLR2 Collect and Display. Circulate, listen for and collect the language students use as they talk about the clocks. On a visible display, record words and phrases such as: half past, hour hand, minute hand, o’clock. Invite students to borrow language from the display as needed, and update it throughout the lesson.
Advances: Conversing, Speaking
Representation: Access for Perception. To ensure access for students with color blindness, label the colors on visual displays and student tasks. Provide colored pencils, crayons, or markers that have labels to indicate color.
Supports accessibility for: Visual-Spatial Processing

### Required Preparation

• Each student needs red and blue colored pencils, crayons, or markers.

### Launch

• Groups of 2
• Give each student a red and a blue colored pencil, crayon, or marker.
• Display clock cards for 9:00 and half past 9.
• “Which card shows 9 o’clock and which card shows half past 9?”
• 1 minute: partner discussion
• Share responses.

### Activity

• Read the task statement.
• 5 minutes: partner work time

### Student Facing

What time is shown on each clock?

If the time is half past, color the clock red.

If the time is o’clock, color the clock blue.

Write the time in words using half past or o’clock.

1.

2.

3.

4.

5.

6.

### Student Response

Teachers with a valid work email address can click here to register or sign in for free access to Student Response.

### Advancing Student Thinking

Students may say that a time is half past the greater number of the two numbers the hour hand is between because the arrow is pointing at a position lower (or past) the greater number when looking at the numbers from top to bottom. Ask students to explain their method for telling the time. Consider asking:

• “Can you show me how the arrow hand moves around the clock? Start at the 12.”
• “Which number do you say first when you count from 1 to 12? Which number does the hour hand pass by first on its way around the clock?”

### Activity Synthesis

• Display clock showing half past 2.
• “Mai says it’s half past 2, and Tyler says it’s half past 3. Who do you agree with? Why do you agree with them?” (I agree with Mai because when you start at the top of the clock and go around, you start at 1, then 2. The hour hand is putting past 2. It looks like its pointing in between 2 and 3).

## Activity 3: Notice and Wonder: The Hands on the Clock Go Round and Round (10 minutes)

### Narrative

The purpose of this activity is for students to connect their understanding of half of a circle to the minute hand moving halfway around the face of a clock (MP7). Students watch a display clock to see that as the minute hand goes around the clock, the hour hand goes from one hour to the next. In the activity synthesis, students add the minute hand to their half-past clock cards. In the next lesson, students will connect half past to 30 minutes to write times in hours and half hours.

Use a display clock set to 10:00 and show the minute hand moving around until the clock shows 11:00. If a display clock is not available, this video can be used.

### Required Preparation

• Each student needs their Half Past Clock Cards from a previous activity.

### Launch

• Groups of 2
• Display the clocks in the student book.
• “What do you notice about these clocks?” (One shows 4 o’clock and the other shows half past 4. One is shaded. Half of the clock is shaded.)
• “Now we will watch the hands on the clock move as time goes by.”

### Activity

• Display demonstration clock or video.
• “What do you notice? What do you wonder?”
• 1 minute: quiet think time
• 1 minute: partner discussion
• Share and record responses.

### Student Response

Teachers with a valid work email address can click here to register or sign in for free access to Student Response.

### Activity Synthesis

• “When the minute hand moves all the way around the circle, a whole hour has passed. The hour hand moves from one hour to the next. When the minute hand moves halfway around the clock, the hour hand moves halfway from one hour to the next.”
• “Let’s put the minute hand on our new half past clock cards.”

## Lesson Synthesis

### Lesson Synthesis

“We’ve looked at clocks that show times in hours and half-hours.” Display clock cards showing 2 o’clock and half past 2.

“What is the same about these clocks? What is different?” (They both have two hands. On the 2:00 clock the minute hand points to the 12, but on the half past clock the minute hand points to the 6. On the 2:00 clock the hour hand points right at the 2, but on the half past clock it points between 2 and 3.)

## Cool-down: Find 2:30 (5 minutes)

### Cool-Down

Teachers with a valid work email address can click here to register or sign in for free access to Cool-Downs.