• Observe and assess students during the Lesson 3 activities.
• Ordering and Comparing Numbers Worksheet (M-K-2-3_Ordering and Comparing Worksheet and KEY.docx) can be used as a formative assessment.

“Today we are going to compare numbers using the words greater than and less than.” Write the words on the board. “There is a symbol mathematicians use for each of these words.” Draw each symbol (< and >) on the board under the appropriate word.

Build the number 15 using base-ten blocks. Then build the number 19 with base-ten blocks. Tell students that the number 15 has 1 ten and 5 ones. Tell them that the number 19 has 1 ten and 9 ones. Then say, “The number 19 is greater than 15. The number 15 is less than 19.” Write “19 > 15” and “15 < 19” as you say it. “I know 19 is greater than 15 because each number has 1 ten, so then I look at the number of ones each number has. The number 19 has more ones than the number 15.”

Point out that the greater-than and less-than symbols resemble open mouths. Ask students, “If you were very hungry, would you rather eat 4 cookies or 10 cookies?” (10) Write 4 < 10, emphasizing that the symbol looks like a mouth eating the greater number. Ask, “Would you rather have 17 donuts or 2 donuts?” (17) Write 17 > 2, again emphasizing that the symbol looks like a mouth eating the greater number. Encourage students to refer to this strategy whenever they need help remembering the meaning of the symbols: The mouth always wants to eat the larger number!

Continue with the following numbers:

• 18 and 12
• 13 and 17
• 20 and 11

For each pair of numbers, have students build both numbers using base-ten blocks. Then have them write each number on a whiteboard. Next, ask the following questions (changing the numbers to match the different number pairs):

• “How many tens are in the number 18?” (1)
• “How many tens are in the number 12?” (1)
• “How many ones are in the number 18?” (8)
• “How many ones are in the number 12?” (2)
• “Is 18 greater than or less than 12?” (greater than)

Have students write the greater-than or less-than symbol between the numbers they wrote on their whiteboard. If students struggle to choose the correct symbol, remind them to think of it like a hungry mouth.

Next write the numbers 12, 18, and 11 on the board. “I can put these numbers in order from greatest to least. To do that I first look at the tens place. 12, 18, and 11 all have one ten. Next, I look at how many ones each number has. 12 has 2 ones, 18 has 8 ones, and 11 has 1 one. 18 has the greatest number of ones, so that is the largest number. 12 has more ones than 11, so 12 is greater than 11.” As you say this, write the numbers in order on the board.

Write the numbers 13, 19, and 14 on the board. Have students order these numbers from greatest to least on their whiteboards.

Then repeat the procedure but instead ordering from least to greatest, using the numbers 14, 12, and 18 for the teacher example and the numbers 15, 17, and 13 for the student example.

Distribute the Ordering and Comparing Numbers Worksheet (M-K-2-3_Ordering and Comparing Worksheet and KEY.docx), and monitor students as they complete it to see who needs additional practice with ordering and comparing numbers.

Extension:

• Routine: Students draw two number cards (M-K-2-1_Number Cards 11-20.docx) and place them on their whiteboard. Students then insert the greater-than or less-than symbol between the numbers. Students draw three number cards and put them in order from greatest to least or least to greatest.
• Small Group: For students who need additional practice, repeat the Lesson 3 activities in a small group.
• Expansion: Use the resources and/or activities provided in the links listed under Related Resources for additional practice, and for enrichment use larger numbers.