In the Same-Change Subtraction app the user can keep adding or subtracting the same amount from both numbers until the subtraction problem can be solved easily. The same-change rules states that If you subtract or add the same number from both parts of a subtraction problem, the difference remains the same. A subtraction problem 667 – 289 is easier to solve if it is changed into 678 – 300. Features: - The numbers can have up to 3 digits - You can set your own problems Other iDevBooks math apps iDevBooks math apps have been reviewed and endorsed by Wired.com, Common Sense Media, and other respected sites and organizations. Feedback and requests for new features New ideas to make this app better are welcome. Please visit idevbooks.com to give feedback. Privacy This app has no ads or in-app purchases and it does not transmit any data during the operation of the app. This app also does not contain any links to other apps or the web.