# 2.NBT.A.3*

Read and write numbers to 1000 using base-ten numerals, number names, and expanded form.

*TNCore Focus Standard

## Summary:

This particular standard expands on students’ previous knowledge of basic numbering skills. Students should recognize, read, and write the numerals through 1000 as well as their expanded form, and also be able to produce representations on their own. For example, students should recognize and explain that 345 as 345, 300 + 40 + 5, and as three hundred forty-five.

## Understanding the Standard:

• Provide opportunities for students to decompose numbers through 1000. This exploration should incorporate activities that help students identify the value of each digit. For example, 537 is 5 hundreds, 3 tens, and 7 ones. Therefore, 5 hundreds has a value of 500, 3 tens has a value of 30, and 7 ones has a value of 7. So, 500 + 30 + 7 is the expanded form of 537.
• Provide activities that will allow students to see numerals to 1000 in a variety of representations (e.g., word form, base ten model, digits, as a picture representation, etc.).

## Questions to Focus Instruction:

• Can students recognize the written forms of numerals to 1000?
• Can students explain their choices and reasoning?
• Are students comfortable with all three representations of numbers (i.e., base-ten numerals, number names, and expanded form)?
• When a number is read aloud, or is written in words or in numeral form, or is represented concretely via objects, or is given in expanded form, are students able to represent the number as a base-ten numeral, to write the corresponding number name, and to write down its expanded form? For example, 232 is 2 hundreds, three tens, and 2 ones, and its exapanded form is two hundred thirty two.
• Can students write the expanded form of a number up to 1000?
• When a number is given in several different forms (for example, the number is read aloud, or is written in words or in numeral form, or is represented concretely via objects, or is given in expanded form), can students 1. recognize the number, and say its name; 2. write the number as a base-ten numeral; and 3. express the number in expanded form?

## Skills

Prior to: Students can represent the numbers with drawings and concrete models. Go to 1.NBT.A.1 to see the previous skills in this progression.