Place Value Patterns

Learning Resource Type

Learning Activity

Subject Area

Mathematics

Grade(s)

2

Overview

In this task, students will be exploring number patterns as they add or subtract ten and as they add or subtract 100. The students will see what happens to the digit values in numbers as they work through this activity.

Phase

During/Explore/Explain
Mathematics (2019) Grade(s): 2

MA19.2.13

Mentally add and subtract 10 or 100 to a given number between 100 and 900.

UP:MA19.2.13

Knowledge

Students know:
  • use place value models for adding and subtracting numbers from 1 to 1000.
  • use strategies for mentally adding and subtracting multiples of 10 and 100.

Skills

Students are able to:
  • use patterns and regularity in counting sequences and understandings of place value to add or subtract a "ten" or a "hundred".
  • communicate reasoning and solution strategies.

Understanding

Students understand that:
  • the digits of a 3-digit number represent amounts of hundreds, tens and ones.
  • patterns in the place value system can be used to mentally compute sums and differences.

Learning Objectives

The students will be able to mentally add and subtract 10 or 100 to a given number between 100 and 900.

Activity Details

The teacher will display the slideshow Place Value Patterns to the class. (The essential questions for the teacher to use are in the notes section of each slide. The students will answer the questions in their math journal or on paper.)

Example questions from the add/subtract 100 slides include:

  1. What do you notice about the value of each place value? What is changing the 100s, 10s, and or 1s? 
  2. Does the 100s place always change? Explain. 
  3. Do any of the other place values change? Why or why not? 

Assessment Strategies

  • The teacher will observe student responses to determine student understanding of the concept and skill.
  • The teacher can use the following guidelines to ensure students meet the learning objective:

Check that the student:

  1. can mentally add/subtract ten or 100 to any number between 100 and 900.
  2. can explain the pattern they see using place value vocabulary.

Variation Tips

  • The teacher may use a 1000s chart in small groups for remediation.
  • The students could highlight as they add/subtract ten and 100 to create a visual.

Background / Preparation

  • The teacher will need a computer and projector to display the slideshow.
  • Students will need a pencil and math journal/paper.
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