Add and subtract 10 from 247. What do you notice when looking at the three numbers? What about when you add and subtract 100 from 247?

Starting at 765, how many groups of ten will you need to add to get to 805? Starting at 329, how many groups of hundred will you need to add to get to 929? (reverse these question types for subtraction)

How does a hundred chart help you when you are adding and subtracting 10 from a number like 57? (or multiple groups of 10 such as 30 and 50)

How does a number line help you when adding or subtracting 100 from a number like 432? (or multiple groups of 100 such as 200 or 600)

Caroline is solving 72 + 10. She is using a hundred chart. She starts on 72 and counts 73, 74, 75, etc. until she gets to 82. Paul says there is an easier way to find the answer using the hundred chart. What do you think Paul will tell Caroline?

About the Math

Students who are forced to rely on algorithms and procedural understanding of mathematics struggle with the ability to fluently add and subtract 10 and/or 100 to numbers. These students often try to rewrite the problem in an algorithmic fashion because they believe that is what they have to do to do math. Essential vocabulary for this standard includes: tens, hundreds, digit, value, skipcount, ones, place, rows & columns (for visualizing hundreds chart), add, subtract, forward, backward, sum, and difference(online dictionary, visual mathematics dictionary, HCPSS Vocabulary Cards).

Rich Tasks for Multiple Means of Engagement, Expression, and Representation (UDL)

Teaching Student-Centered Mathematics, K-3

Skip Count patterns, p. 138
Skip count by 10s or 100s as a class, varying your starting number. After counting together as a class, ask students to record a specific skip-count pattern using a 100s chart or 1000s chart. Ask students to observe what they recorded, looking for a pattern and then ask them to describe what they see. Ask them what they notice and if they can describe their patterns using math vocabulary.

More and less on the hundreds chart, p. 139 Models with the hundreds chart, p 139 The thousands chart, p. 139 Digit change, p. 140 Calculator skip counting, p. 285 Fractured chart pieces, p. 288

Hands On Standards (3-4), Adding and Subtracting, pages 20 - 21

The Super Source Base Ten Blocks grades 3-4 Ten, Ten, Ten: pages 74-75

Facts That Last, Addition Adding Ten Strategy, pages 64 - 67

Navigating through Number and Operations Trading Up or Down: Pages 23- 25

Math Intervention: Building Number Power PreK-2 Adding and Subtracting Tens pg. 122-124

Nimble with Numbers, Grade 1 & 2, Fifty Chart Pieces, pages 106 - 107 Find My Number, pages 108 - 109 What's in that Place, pages 110 - 112 Claim All You Can, pages 115 - 116 Fill in the Pieces, pages 121 - 122

Mental Math in the Primary Grades, Skip Counting by 5s, 10s, 100s, pages 49 - 50 Patterns on the Hundred Chart, pages 51 - 52 Tracing Paths on the 100 Chart, pages 53 - 54 Arrow Moves on the 100 Chart, pages 55 - 56 Using the 100 Chart to +/- 10s and 1s, pages 57 - 58 Using the 100 Chart to +/- Multiples of 10, pages 59 - 60

## Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.

Quarter 1Quarter 2Quarter 3Quarter 4(continue through routines and classroom discussion)

(continue through routines and classroom discussion).

(continue through routines and classroom discussion)

(continue through routines and classroom discussion)

(continue through routines and classroom discussion)

## Increasing Rigor

Students who are forced to rely on algorithms and procedural understanding of mathematics struggle with the ability to fluently add and subtract 10 and/or 100 to numbers. These students often try to rewrite the problem in an algorithmic fashion because they believe that is what they have to do to do math. Essential vocabulary for this standard includes:About the Mathtens,hundreds,digit,value,skipcount,ones,place,rows&columns(for visualizing hundreds chart),add,subtract,forward,backward,sum, anddifference(online dictionary, visual mathematics dictionary, HCPSS Vocabulary Cards).Rich Tasks for Multiple Means of Engagement, Expression, and Representation (UDL)## Teaching Student-Centered Mathematics, K-3

Skip Count patterns, p. 138Skip count by 10s or 100s as a class, varying your starting number. After counting together as a class, ask students to record a specific skip-count pattern using a 100s chart or 1000s chart. Ask students to observe what they recorded, looking for a pattern and then ask them to describe what they see. Ask them what they notice and if they can describe their patterns using math vocabulary.

More and less on the hundreds chart, p. 139Models with the hundreds chart, p 139The thousands chart,p. 139Digit change, p. 140Calculator skip counting, p. 285Fractured chart pieces, p. 288## Learnzillion Video Resources (6 Lessons)

Additional Lesson Sets from Learnzillion:Print Resources:Hands On Standards (3-4),Adding and Subtracting, pages 20 - 21The Super Source Base Ten Blocks grades 3-4Ten, Ten, Ten: pages 74-75Facts That Last, AdditionAdding Ten Strategy, pages 64 - 67Navigating through Number and OperationsTrading Up or Down: Pages 23- 25Math Intervention: Building Number Power PreK-2Adding and Subtracting Tenspg. 122-124Nimble with Numbers, Grade 1 & 2,Fifty Chart Pieces, pages 106 - 107Find My Number, pages 108 - 109What's in that Place, pages 110 - 112Claim All You Can, pages 115 - 116Fill in the Pieces, pages 121 - 122Mental Math in the Primary Grades,Skip Counting by 5s, 10s, 100s, pages 49 - 50Patterns on the Hundred Chart, pages 51 - 52Tracing Paths on the 100 Chart, pages 53 - 54Arrow Moves on the 100 Chart, pages 55 - 56Using the 100 Chart to +/- 10s and 1s, pages 57 - 58Using the 100 Chart to +/- Multiples of 10, pages 59 - 60Web Resources:Games and CentersLessonsStudent ResourcesVideo SegmentsYouTube video

Center activity

printable game

Teacher guide for virtual manipulatives 2.NBT.8

Literature Connections:Earth Day Hurray

Place Value by 10’s and 100’s

By Stuart Murphy

## Questions/Comments:

Contact John SanGiovanni at jsangiovanni@hcpss.org.Use and Sharing of HCPSS Website and ResourcesHoward County Public Schools Office of Elementary Mathematics Curricular Projects has licensed this product under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.