The integers and order of operations of this App needs some serious overhaul. I became frustrated and watched Kahn Academy to see where I was falling short. Every problem that I worked through with Kahn, determined that my answers were correct. I went back to this app to test, and got many wrong. Feeling deflated, I asked my husband to check my work. He’s an electrical engineer and has been for 30 years. He also has his masters in systems engineering, so he deals with complex math everyday. After checking my work, he found that my answers were correct and this App to be wrong. Save yourself the trouble and headache and don’t purchase this program.