**Click here for the Spanish Version**: **https://youtu.be/uO-TDHj5e0g**

**In This Unit of Study…**

Students use concrete models to form bundles of 100s with and without leftovers. Students then use concrete and pictorial representations to investigate how three-digit numbers can be composed and decomposed in different combinations within the hundreds, tens and ones place values. Students use a place value mat along with the models to represent the quantities with corresponding written numerals, and they interpret the place value of each digit’s position within a written numeral. Students read and write numbers to 1,000 in standard, expanded, and word form. Students apply what they know about the sums of doubles (to 20) to represent even (by using two equal groups/addends) and odd numbers (by using two equal groups/addends with one left over).

**B.E.S.T. Benchmarks:**

- MA.2.NSO.1.1 Read and write numbers from 0 to 1,000 using standard form, expanded form and word form.
- MA.2.NSO.1.2 Compose and decompose three-digit numbers in multiple ways using hundreds, tens and ones. Demonstrate each composition or decomposition with objects, drawings and expressions or equations.
- MA.2.NSO.2.1 Recall addition facts with sums to 20 and related subtraction facts with automaticity. (doubles)
- MA.2.AR.3.1 Represent an even number using two equal groups or two equal addends. Represent an odd number using two equal groups with one left over or two equal addends plus 1.

**Key Concepts:**

- I can read and write numbers to 1,000 using standard form, expanded form, and word form.
- I can determine whether a group of objects (up to 24) has an odd or even number by pairing objects or counting them by twos.
- I can write an equation to express an even number as a sum of two equal addends.
- I can understand that three digits of a three-digit number represent amounts of hundreds, tens, and ones, which are included in special cases such as:
- 100 can be thought of as a bundle of ten tens—called a hundred.
- The numbers 100, 200, 300, 400, 500, 600, 700, 800, and 900 refer to one, two, three, four, five, six, seven, eight, and nine hundreds (and 0 tens and 0 ones).

- I can count within 1,000 skip counting by fives, tens, and hundreds.
- I can demonstrate how to compose and decompose three-digit numbers with objects, drawings, and expressions or equations.