The purpose of this Choral Count is to invite students to practice counting by 1 from 90 to 120 and notice patterns in the count. Keep the record of the count displayed for students to reference throughout the lesson. When students notice the patterns in the digits after counting beyond 99 and explain the patterns based on what they know about the structure of the base-ten system, they look for and express regularity in repeated reasoning (MP7, MP8). Students will develop an understanding of a hundred as a unit and three-digit numbers in grade 2.
Launch
“Count by 1, starting at 90.”
Record as students count.
Stop counting and recording at 120.
Activity
“What patterns do you see?”
1‒2 minutes: quiet think time
Record responses.
Student Task Statement
None
Student Response
Loading...
Advancing Student Thinking
Activity Synthesis
“What do you notice about the numbers we counted?" (Some only have 2 digits and some have 3. After 100, I see the numbers 1–20 again.)
Activity 1
15 mins
Measure Animal Lengths
Standards Alignment
Building On
Addressing
1.MD.A.2
Express the length of an object as a whole number of length units, by laying multiple copies of a shorter object (the length unit) end to end; understand that the length measurement of an object is the number of same-size length units that span it with no gaps or overlaps. Limit to contexts where the object being measured is spanned by a whole number of length units with no gaps or overlaps.
The purpose of this activity is to count groups of between 95 and 120 length units and represent the count using representations of tens and ones. Each group measures a strip of tape using centimeter cubes. They determine how to count the cubes and create a representation. Students may group their cubes and count by tens and ones. Some students may group 10 tens as 100.
MLR2 Collect and Display. Circulate, listen for, and collect the language students use as they measure their animals. On a visible display, record words and phrases such as: lengths, tower, cubes, measure, long. Invite students to borrow language from the display as needed, and update it throughout the lesson. Advances: Speaking, Reading
Representation: Internalize Comprehension. Begin by asking, “Does this situation remind anyone of something we have done before? How so?” Supports accessibility for: Conceptual Understanding, Memory, Attention
Launch
Groups of 3
Give each group centimeter cubes.
Assign each group to a strip of tape.
Activity
“Around the classroom are strips of tape that show the lengths of different animals. Each group will measure one animal and determine how to count the cubes. Show your thinking using drawings, numbers, or words.”
8 minutes: small-group work time
Student Task Statement
Animal:
Length:
Show your thinking using drawings, numbers, or words.
Activity Synthesis
Display 11 towers of 10 and 3 single cubes.
“These are the cubes used to measure a different animal. How can we figure out the length of this animal?”
Activity 2
20 mins
Write Numbers to Represent Animal Lengths
Standards Alignment
Building On
Addressing
1.MD.A.2
Express the length of an object as a whole number of length units, by laying multiple copies of a shorter object (the length unit) end to end; understand that the length measurement of an object is the number of same-size length units that span it with no gaps or overlaps. Limit to contexts where the object being measured is spanned by a whole number of length units with no gaps or overlaps.
The purpose of this activity is for students to write numbers between 95 and 120. Groups create posters that show a drawing of how they counted their animal measurements from the last activity. Groups should not write a number for the final measurement on their posters. Students do a Gallery Walk to interpret each representation and record the count with a number in their workbooks. Group members then compare their counts and written numbers.
When students look at the different representations and determine the length of each animal, they may notice that the representation may help to accurately find the value. For example, students may draw groups of 10 cubes rather than every individual cube (MP7).
This activity uses MLR7 Compare and Connect. Advances: representing, conversing.
Launch
Groups of 3
Give each group tools for creating a visual display.
Activity
MLR7 Compare and Connect
“Create a poster to show how you counted the cubes you used to measure the length of the animal in the measuring animals activity. Do not write the number of cubes your animal measured on your poster.”
Make sure each group writes the name of their animal on their poster.
5 minutes: group work time
“Now we will do a Gallery Walk to see different representations of your measurements. As you look at each poster, use the representation to determine the length of the animal. Write the number of cubes that represents its length in your book.”
7 minutes: Gallery Walk
Student Task Statement
Write the number of cubes that represents each animal’s length.
The beaver is cubes long.
The dog is cubes long.
The anteater is cubes long.
The raccoon is cubes long.
The red fox is cubes long.
The snake is cubes long.
Activity Synthesis
Display the snake and giant anteater posters.
“How do I write the number that represents the length of the red fox?”
“Where do you see 100 in this poster? Where do you see 5?”
Repeat for anteater.
Lesson Synthesis
“Today we wrote numbers up to 120. Let’s count by 1. Start at 100. I will write each number we say.”
Record the count.
“How would you explain writing numbers from 100 to 120 to a friend?” (There are 3 digits. The first digit is a 1. The pattern of writing numbers from 1–20 is the same.)
Student Section Summary
We used different objects to measure length.
How to Measure Length with Objects
Use objects that are the same length.
Line up the objects end-to-end.
Do not have gaps or overlaps.
Count the number of objects.
The shoe is 15 cubes long.
We used more objects to measure longer lengths.
We grouped the objects to make them easier to count.
We counted and wrote numbers from 100 to 120.
Jada measures the length of the teacher’s desk. She uses small cubes.
The teacher’s desk is 117 cubes long.
Have feedback on the curriculum?
Help us improve by sharing suggestions or reporting issues.