M 2.3

Express numbers in usual and expanded form: Up to 3 digits; Use place value to name number that is 10, 100 more than or less than a given number; Recognize that every place value is 10x bigger than the place value to the right

Noun - 3 Digit Numbers

Verb - Express, Recognize

Content: Expanded Notation

Related Article:

The links below is a link related to Expanded Notation:

• https://www.youtube.com/watch?v=u3JJt8f3B30
• https://www.thoughtco.com/expanded-notation-lesson-plan-2312844

Instructional Strategies & Learning Tasks

Manipulative:

1. Base ten materials
2. Place Value Chart

Instructional Strategies

• Review place value chart and the patterns involved. Show the relationship of one column to another, from right to left and from left to right.
• Model all numbers with base ten materials to represent 10 times and 100 times a given number.
• Ask students to imagine in their minds a slinky toy. Describe to the students how it starts off small but it can be stretched out, or expanded. An expanded number is similar to a slinky, in how you can stretch out the digits to see its value in a different way.
• Explicitly show on chart paper a place value chart and review the headings of the place value chart. Model placing 2 digit numbers on the chart and explain how to stretch out the number into 20+5, for 25.
• Ask children to write down on their whiteboard a place value chart. Then get them to record a 3 digit number that you say aloud. Tell them that this usual way we write numbers is called the standard form.
• Examine the digits of this 3 digit number and others and discuss their value within the place value chart.

For example: 345

Hundreds Tens ones

3 4 5

300 40 5

= 300 + 40 + 5

• Model using a PowerPoint or on the board how to take more 3-digit numbers, put them into the place value chart, and then write out the values of each digit. Express to students that 2 digit and 3 digit numbers are like adding the ones with the tens and hundreds. When we write that out and add together each digit, we are showing the number in expanded form. Just like a slinky that is pulled apart, numbers can be stretched to show their value.
• Find a You tube video called Expanded Form Video - 1st and 2nd Grade Math to add to student understanding.
• View place value chart headings. Ask: What do you notice about each heading as you move to the left? Show students that each time you move the place value of a digit to the left you multiply it by 10. Explicitly show on the board moving a number 1 from the ones place to the tens, and how you multiply the 1 by 10. Then move the one to the hundreds place and multiply the 10 by 10.

Learning Tasks:

Task 1

• Ten Times Test: Roll a number cube or cubes. Student takes ten times the amount rolled and places the base ten materials on the place value chart. Target number = 999 or 1 000. Variation: Roll doubles and lose all your base ten blocks.

Task 2

• Hundred Times Test: Roll two number cubes. Student takes one hundred times the amount rolled and places the base ten materials on the place value chart. Roll a number greater than five and lose all your base ten blocks. Roll doubles and student must subtract amount from the place value chart.

Task 3

• Pair and share: Students look at a given two-digit number on the board and discusses with their partner how many tens and ones there are in the number. Do the same with 3 digit numbers.

Task 4

Value Rumble! Write several 3 digit numbers on the board and toss a ball to a student who will give the answer. Use a pointing stick to direct the student to one of the digits of one of the numbers, and have the student state the value of the digit you have chosen. The ball then gets tossed to a new students and the teacher points to a different digit and continues the game.

Task 5

Value Stretch! Ask students to write down a 3 digit number of their own choice. Ask student to exchange numbers with a partner and then write the expanded form of their new number underneath. Share some of the results and discuss as a class.

Task 6

Reverse Reverse! As a mental math activity: Flash the expanded form of numbers onto the board. Have students write the number in standard form as quickly as they can.

Assessment

Task 1

Number Formation: Does the student arrange three digit numbers correctly? Does the student write numbers in standard and expanded form correctly or does students miss one, or two digits when writing?

Task 2

Proper placing of number on place value chart : Ask students to identify each place Value on the place Value chart. Does the student place each number under its correct value? Is the student able to differentiate between two different values? Can the students read numbers with their place value correctly?

Task 3

At the end of a lesson, give students an exit slip with 2 three-digit numbers on it. Ask students to write the numbers in expanded form and write their name. Collect these to assess whether students can write the number in expanded form correctly.

Task 4

Prepare a short mental math quiz. Can students write the usual form of numbers when given in expanded form?

Task 5

Math interview: No paper required.

After the majority of the unit has been taught. Meet quickly with students individually to check for understanding. Ask them 3 questions:

a) Show student 2 different numbers on the same place value chart. Ask student what the difference is between the two numbers?

b) Verbally tell student a 3-digit number and have them tell you it in expanded form verbally.

c) When you move a number to the left in the place value chart, what do you multiply the number by each time you move it?

Sample Lesson Plan