Use two colors of base ten blocks to help students build their number sense and gain a visual and concrete understanding of what it means to add two 2-digit numbers. Use these lessons and activity pages to introduce and practice the idea of composing a ten (regrouping).
This activity is AMAZING for helping students' mental math skills when adding 2-digit numbers - they learn to visualize what will happen with the tens and ones when they add numbers together. Very soon, they discover, "I can do this in my head!" :)
Included in this packet:
• Lesson plan
• Work Space with two 1-100 charts (each pair of students shares a work space; later, when children are ready to do this task independently, every student will need one). These Work Space papers are designed to fit standard (1 cm) base ten blocks.
• Blank hundred charts that can be copied on colored cardstock and cut apart if you don't have base ten blocks.
• SIX front-and-back student pages for students to complete. I would suggest having all students complete page 1 with a partner (one partner models the first number on the top Work Space chart, the other models the second number on the bottom chart, then both work to add their numbers together). Some students will benefit from having a partner to complete page 2; others will be ready to work independently.
• Answer keys
*REVISED August 2015 to add student pages (new total: six pages) and complete lesson plans and answer keys.