In the Opposite-Change Addition app the user can keep adding a number to one addend and subtract the same number from the other addend until the addition problem can be solved easily.

The opposite-change rules states that if you subtract a number from one addend and add the same number to the other addend, the sum remains the same. An addition problem 267 + 289 is easier to solve when it has been changed into 256 + 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.

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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.