Help your students master addition with regrouping within 1000 with these practice worksheets! Perfect for 1st-4th grade. They can be used for extension, on grade level practice, assessment, data collection, review, or for intervention work. There are two differentiated versions available. One version has 10 practice problems while the other version asseses the same standard/skill but has 5 problems on it. These worksheets are ideal for morning work, math centers, homework, guided practice, IEP