These five apps can help middle school students learn math skills such as geometry, estimation, and simple algebra
Here are reviews of five high-quality digital apps that can help teach middle school math, courtesy of Common Sense Media and its new Graphite  service—a free database of teacher-written reviews of learning technologies.
Grade range: 3-7
What is it? Divide and conquer with clever puzzles that build a geometry foundation.
Pros: Trial-and-error game play supports nimble discovery of concepts and strategies.
Cons: Lacks explicit connection between game principles and classroom learning.
Bottom line: A fun way for kids to jump into geometry with lessons on shapes, symmetry, and area.
Full review: http://www.graphite.org/app/slice-it 
What is it? Estimation becomes a fabulous math game.
Pros: Exposes kids to estimation in fun ways, with concrete math explanation.
Cons: Number ranges aren’t limited at first, so it’s easy for answers to be way off.
Bottom line: A great-looking, fully engaging math experience, from question to answer.
Full review: http://www.graphite.org/app/questimate 
What is it? A nice twist to learn equation steps, not answers.
Pros: Students get encouraging words at each step.
Cons: You can’t track how students are progressing, or if they’re progressing at all.
Bottom line: Algebra Touch breaks equations down into steps and describes them with such basic language that math-challenged students should improve.
Full review: http://www.graphite.org/app/algebra-touch 
What is it? Mesmerizing, step-by-step puzzler sets the foundation for algebra.
Pros: A truly elegant design integrates entertainment and instruction so seamlessly that playing = learning.
Cons: Some levels might be hard to solve without hints.
Bottom line: This innovative game-changer teaches algebra, changes the way kids learn it, and even changes how they feel about it.
Full review: http://www.graphite.org/app/dragonbox-algebra 
Motion Math: Pizza!
What is it? Serving up valuable economics lessons with an extra helping of fun.
Pros: The challenges and rewards of running a successful business will empower kids and keep them engaged.
Cons: Could use more instructions and hints for kids who need extra guidance.
Bottom line: Fantastic math game gives kids a taste of what’s needed to run a profitable business.
Full review: http://www.graphite.org/app/motion-math-pizza