Interactive
Arcademics

Arcademics: Four Wheel Fracas

For Students 6th
Multiplayer math game where four wheelers race by solving algebra one-step addition and subtraction problems.
Activity
OnlineMathLearning.com

Online Math Learning: Adding & Subtracting Positive & Negative Decimals

For Students 7th
An interactive worksheet for practice in the addition and subtraction of decimals with positive and negative signs.
Lesson Plan
Better Lesson

Better Lesson: Hopping Up & Down the Number Line

For Teachers K Standards
SWBAT identify the subtraction and addition sign and understand their function by hopping a bunny up and down a number line.
Unit Plan
Texas A&M University

Wtamu Virtual Math Lab: College Algebra: Adding & Sub. Rational Expressions

For Students 9th - 10th Standards
Rational expressions have never been so easy! Use this site to learn how to add and subtract them with ease and confidence. And common denominators? No Problem! Great practice problems are included to see how much you've learned.