Student Probe Expanded Notation At a Glance
Write 347 in expanded notation. Lesson Description This lesson expects the student to change a number from standard form to expanded notation. Rationale To be successful with computation and later mathematics, students must be able to compose and decompose numbers. An understanding of the base ten numeration system can be partially demonstrated by decomposing numbers into expanded notation. Preparation None Lesson The teacher says or does… 1. Ask the student to write the number 426 in expanded notation in at least two ways. 2. How many tens are in 426? What: Write base ten numbers in expanded notation Common Core Standards: CC.2.NBT.3. Read and write numbers to 1000 using base‐ten numerals, number names, and expanded form. Mathematical Practices: Attend to precision. Look for and make use of structure. Who: Students who cannot decompose numbers by place value Grade Level: 2 Prerequisite Vocabulary: hundreds, tens, and ones Prerequisite Skills: Base ten representation Delivery Format: individual, small group, or large group Lesson Length: 15‐20 minutes Materials, Resources, Technology: Base ten blocks Student Worksheets: None Expect students to say or do… 4 hundreds + 2 tens + 6 ones 4 hundreds + 1 ten + 16 ones 4 hundreds + 0 tens + 26 ones 3 hundreds + 12 tens + 6 ones etc.
42 tens in 426 If students do not, then the teacher says or does… Refer to Base Ten Representation ‐‐ Grouped Models. Ask the student to exchange the hundred flats into ten rods. Count the number of ten rods. If the student doesn’t understand, count the ten rods on the hundred flats. The teacher says or does… Expect students to say or do… 3. How many ones are in 426? 426 ones in 426 If students do not, then the teacher says or does… Ask the student to exchange the 42 rods into units. Count the number of units. If the student doesn’t understand, count the units on the hundred flats, ten rods, and single units. Teacher Notes Continue asking the student to change numbers in standard notation into multiple expanded notations and ask similar questions: How many tens in the tens place in____? How many ones in the ones place in _____? If necessary, allow the student to use pre‐grouped models such as base ten blocks. Variations None Formative Assessment Write the number 594 in expanded notation. How many tens in the tens place in 594? How do you know? How many hundreds in the hundreds place in 594? How do you know? References Russell Gersten, P. (n.d.). RTI and Mathematics IES Practice Guide ‐ Response to Intervention in Mathematics. Retrieved Feb. 25, 2011, from rti4sucess Van de Walle, J. A., Karp, K. S., & Bay‐Williams, J. M. (2010), Elementary and Middle School Mathematics Teaching Developmentally, 7th Ed.