# Lesson 17

Compare and Order Numbers

## Warm-up: Which One Doesn’t Belong: Comparison Statements (10 minutes)

### Narrative

This warm-up prompts students to compare four comparison statements. It gives the teacher an opportunity to hear how students use terminology and talk about characteristics of the items in comparison. During the synthesis, ask students to explain the meaning of any terminology they use, such as comparing, greater than, and less than.

### Launch

• Groups of 2
• Display the image.
• “Pick one that doesn’t belong. Be ready to share why it doesn’t belong.”
• 1 minute: quiet think time

### Activity

• “Discuss your thinking with your partner.”
• 2–3 minutes: partner discussion
• Share and record responses.

### Student Facing

Which one doesn’t belong?

### Activity Synthesis

• “How do you know that C is false?” (35 isn't less than 20 because 35 has 3 tens and 20 only has 2 tens.)
• “What could you change about C to make it true?” (Use the greater than symbol or switch the symbol around.)

## Activity 1: Compare and Order Quantities (20 minutes)

### Narrative

The purpose of this activity is for students to compare numbers represented in different ways. Students place the numbers in order from least to greatest. Students may create alternate representations for each number in order to compare them. For example, students may represent each number with a drawing, or write the two-digit number that matches each card (MP2).

MLR2 Collect and Display. Circulate, listen for, and collect the language students use as they order the numbers. On a visible display, record words and phrases such as: greater than, less than, more, less, first, second, third, fourth, order. Invite students to borrow language from the display as needed, and update it throughout the lesson.
Action and Expression: Internalize Executive Functions. To support working memory, provide students with access to sticky notes or mini whiteboards to keep track of the value of each card in the set.
Supports accessibility for: Memory, Organization

### Required Materials

Materials to Gather

Materials to Copy

• Ordering Cards: Tens and Ones

### Required Preparation

• Create a set of cards from the blackline master for each group of 2.

### Launch

• Groups of 2
• Give each group a set of cards and access to connecting cubes in towers of 10 and singles.
• Display the image in the student book.
• “Talk with your partner and decide how to order these cards from least to greatest.”
• 2 minutes: partner discussion
• Share and record responses.

### Activity

• “You will compare numbers and put them in order from least to greatest. Each set has 4 numbers. Start by finding all the cards that have an A on them. Once you have them in order, write them in order on your recording sheet. Then look for the cards that have a B on them and do the same thing. Be ready to share your thinking.”
• 10 minutes: partner discussion
• Monitor for students who:
• make a base-ten drawing for each number and compare the tens, then ones if needed
• write each two-digit number and compare the tens, then ones if needed

### Student Facing

Pick a set of cards.
Put the cards in order from least to greatest.
Be ready to explain how you ordered your cards.

Write the numbers in order from least to greatest.

Set A: ______________________________________________

Set B: ______________________________________________

Set C: ______________________________________________

Set D: ______________________________________________

If you have time:
Mix two sets of cards together.
Put them in order from least to greatest.

### Activity Synthesis

• Display set A.
• Invite previously identified students to share.
• “How are these methods the same?” (They both showed the tens and ones. They both compared tens first.)

## Activity 2: Order Numbers (15 minutes)

### Narrative

The purpose of this activity is for students to compare numbers less than 99 to the benchmark numbers 5, 10, 50, and 99.

Students may use a variety of methods, including considering the relative magnitude of numbers (for example, 49 is one away from 50), the value of the tens and ones (for example, 22 goes after 10 because 2 tens is more than 1 ten), and counting (for example, I know 97, 98, 99) to put the numbers in order. The emphasis is on the order of the numbers rather than the exact placement since this is not a number line. During the synthesis, students share how they ordered the numbers.

### Launch

• Groups of 2
• Display the list of numbers in order from the student workbook.
• “What do you notice? What do you wonder?” (I notice that the numbers go in order. The number 1 is smallest and 99 is the largest. Why are these numbers in this list? Will we add numbers to this list?)
• 1 minute: quiet think time
• 1 minute: partner discussion
• Share responses.

### Activity

• 10 minutes: partner work time

### Student Facing

1. Here are some numbers in order:

1

5

10

50

99

Add these numbers to the list:
• 49
• 8
• 25
• 98
• 13

Make sure all the numbers are in order from least to greatest.

2. Choose 2 numbers. Explain how you knew where to place them.
• I knew where to place $$\boxed{\phantom{\frac{aaai}{aaai}}}$$ because

• I knew where to place $$\boxed{\phantom{\frac{aaai}{aaai}}}$$ because

3. Write a number that makes each comparison statement true.

$$25<\boxed{\phantom{\frac{aaai}{aaai}}}$$

$$25>\boxed{\phantom{\frac{aaai}{aaai}}}$$

### Activity Synthesis

• Display the list of given numbers.
• Invite students to share different methods for determining where to place each number.
• As students share, fill in each number in the correct order.

## Lesson Synthesis

### Lesson Synthesis

“In this section, we compared and ordered two-digit numbers. What are some things that can help us order numbers?” (Compare the digits in the tens place first. If the numbers have the same amount of tens, compare the digits in the ones place. Think about numbers they are close to. Think about the counting sequence.)

## Student Section Summary

### Student Facing

We compared numbers using the number of tens and ones.

17 has 1 ten and 35 has 3 tens so 17 is less than 35.

$$17<35$$
17 is less than 35.

$$35 >17$$
35 is greater than 17.

$$35 = 35$$
35 is equal to 35.