The purpose of this activity is for students to consider the magnitude of numbers ranging from one-digit to three-digits. Students estimate what item in a school might be represented by a given number and also what items could definitely not be represented by that number. When students estimate and make assumptions about what could be in a school building, they model with mathematics (MP4).

• Invite previously selected students to share.
• “Do you agree that this number could represent _____?”
• “How did you use estimation to help you think about what these numbers could represent?” (I know about 5 people walk from home in our class. If there are 4 classes in our grade, that’s about 20 kids that walk in each grade. Then I added 20 for each grade in our school and got 120. I know 120 is close to 110 and maybe there are less kids that walk in some classes or grades.)

The purpose of this activity is for students to think about the quantity of different items in their own classroom. Students begin by sharing different items they think these numbers could not represent. They then make a list of items they think each number could represent. They discuss what work would need to be done to determine if any of their ideas are correct. If time permits, students collect this data and determine what the numbers represent. If students are not able to collect this data, the teacher can reveal what the numbers represent in their classroom. When students collect data or explain how it could be collected, they model with mathematics (MP4).

• “What did your group learn about the quantity of the item you chose?” (We learned that there are way more _____ than we thought. When we counted to 200 and saw that there were still a lot more, we stopped because we knew there were more of this item than the given number. We learned that the given number represented the item we counted.)
• If students have not determined the items represented by the given numbers, reveal each item. Consider counting each item as a class to confirm.