Overarching Standard: MA.1.NSO.1 Extend counting sequences and understand the place value of two-digit numbers.

Benchmark of Focus

MA.1.NSO.1.2: Read numbers from 0 to 100 written in standard form, expanded form and word form. Write numbers from 0 to 100 using standard form and expanded form.

Examples The number seventy-five written in standard form is 75 and in expanded form is 70 + 5.

Related Benchmark/Horizontal Alignment

• MA.1.NSO.2.4

Vertical Alignment

Terms from the K-12 Glossary

• Expression

Purpose and Instructional Strategies

The purpose of this benchmark is for students to understand that the value of a digit is impacted by its position in a number. A three in the tens place has a value of 30 while a 3 in the ones place has a value of 3. In Kindergarten, students learned to recognize and count numbers to 100 verbally. Students counted out objects within 20 when given that number verbally or by its written numeral. (MTR.5.1)

• Instruction includes the understanding that in expanded form each digit of a multi-digit number is assigned a value based on its place.
• Instruction includes experiences with numbers written in different forms. (MTR.2.1 Demonstrate understanding of representing problems in multiple ways)
• Instruction includes the use of both proportional and non-proportional models like base ten models or place value disks. (MTR.5.1)

Common Misconceptions or Errors

• Students may confuse the value of the digits with how they are stated as a number.
• For example, the standard form of fifteen is 15 and not 51.
• Students may write sequences of numbers rather than expanded form like 83 as 8 + 3 instead of 80 + 3. Having students use base ten blocks to model the number could be helpful for students to understand that the value is directly correlated to tens and ones.

• How many tens and ones are in the given number?
• Sample answer: How many tens and ones are in 15? 1 group of tens and 5 ones.
• How can we write __ tens and __ ones in word form? standard form?
• How can we write 1 ten and 5 ones in word form? standard form?
• fifteen; 15
• How can we write (number written in word form) standard form? expanded form?
• How can we write this number using digits?
• How do we write this number using words?
• What is expanded form?
• A way that we can write a number while telling the value of each digit. We create an algebraic expression.
• What is standard form?
• A way we can write a number using digits.
• What is word form?
• A way to write a number using words.

Provide students with the graphic organizer shown below.

Part A. Using tens and ones base ten blocks, create a two-digit number and record in the first column. Write an addition expression in the second column that corresponds to the representation in the first. In the last column, write your number. Repeat until you have created four numbers and written four addition expressions.

Part B. With a partner, review your work and explain how you know your expressions are correct.

Instructional Items

Instructional Item 1

How are 16 and 61 alike and different?

Instructional Item 2

Kourtney wrote a number in expanded form: 90 + 4. What is the standard form of her number?

Instructional Item 3

Using the word form of a number, complete the table below with the missing standard form or expanded form.

Expanded form Lesson

Place Value – Roll It, Draw It, Expand It! (TPT Activity)

Numbers to 1000 (Grades K-2 Nearpod Lesson)

Math Skill Practice (IXL)

Sheriff Jacob: Expanded Form by Kathleen L. Stone (Read Aloud)

Place Value Activities for Kids (BrainPop Educators)

30 Smart Place Value Activities (Blog Post)