Khan Academy
Khan Academy: Adding Negative Numbers on the Number Line
Practice matching number line diagrams to addition expressions involving negative numbers. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Algebra: Number Lines Study Guide
This comprehensive study guide highlights the main terms and formulas needed to review number lines. Examples are included.
Better Lesson
Better Lesson: Rational Numbers and Integer Practice
A lesson for students to practice adding integers, defining rational number, and placing rational numbers on a number line. Included on the page is videos and documents to help execute the lesson.
Visual Fractions
Visual Fractions: Add Fractions With Number Line or Circle Models
This site is provided for by Visual Fractions. Add mixed numbers with like denominators using circles. Click on the "Explain" button to understand the answer.
Better Lesson
Better Lesson: Smoothing Out Subtraction
Second graders demonstrate comfort with addition, but show less ease with subtraction. Repeated practice with subtraction is necessary to build fluency.