Math Flash Cards (Free):

Children can build and improve essential math skills in: addition, subtraction, multiplication and division.

Features include:

• top and bottom number ranges can be edited
• number ranges: 0 to 50 for addition and subtraction
• number ranges: 0 to 20 for multiplication and division
• option to select addition & subtraction or multiplication & division together

• adjustable countdown timer for test-like conditions

• option to allow cards in order (for quicker memorization) or random
• option to show correct answer if wrong
• option to allow three tries
• option to repeated missed cards for review at the end

• friendly and encouraging voice
• scores list to review improvement

This app is free but is support by ads.
A paid ad-free version is also available.