Hundreds Chart Unit of Study: Strengthening Critical Area: Understanding Place Value to Add and Subtract Global Concept Guide: 3 of 3

You may have noticed that Unit 16’s GCG’s look different from the previous units. Unit 16 was provided as a way to strengthen student understanding of the critical area place value. Your student’s performance on the Unit Assessment and Performance Task will be your guide for the activities you select as you progress through this unit.

Content Development Students need to see multiple representations and strategies to add and subtract using place value. They have had many chances to find patterns and count by 1’s and 10’s using a 100/120 chart, and can build on these experiences to add/subtract larger numbers. Using hundred charts to add/subtract larger numbers can build students’ understanding and set a foundation for addition/subtraction with regrouping. Make connections to open number lines and adding on a hundreds chart.

Day 1 Essential Question: How does visualizing the structure of a hundreds chart help you add or subtract? Build a Wacky Hundreds Chart-Cooperative whole group activity where students use number cards to build a Hundreds Chart on the floor. Students will need to communicate about the relationship of numbers (1 more, 1 less, 10 more, 10 less). Students independently complete Hundreds Chart Puzzle. Look for students who struggle with the pattern on Hundred Chart. Be sure to provide support when needed. By the end of Day 1, students will be able to build a Hundred Chart and describe the structure and pattern of the chart.

Day 2 Essential Question: How does using a 120 chart help you compose and decompose numbers? Addition and Subtraction 120 Chart-Students should be using a completed 120 chart to model addition and subtraction. Boards can be laminated or placed in plastic sleeves so students can track their thinking. Have students explain their thinking in terms of tens and ones, and how they moved on the hundreds chart. By the end of Day 1, students will be able to model adding and subtracting on 120 chart as well as explain the pattern. I started at 73. I had to add 25 more, so I moved down two tens and counted on 5 ones.

Students should make connections to adding and subtracting on a hundred chart to their previous work with open number lines. This will be required on the Performance Task. Performance Task will be given at the end Day 2.

Enrich/Reteach/Intervention Using Hundred Chart To Add 1 more/1 less – Interactive activity Subtracting on a Hundred Chart Colored Hundred Chart – help with visualizing patterns Enrich Provide number sentences for adding and subtracting and students will model on Hundred Chart.