Addition And Subtraction Facts To 20 Teaching Resources | TpT Math Fact Fluency Addition and Subtraction to 20. by. Reagan Tunstall. 1.3k. $11.50. Zip. If you are looking for a way to provide systematic fact fluency practice for addition and subtraction up to 20, here it is! These problems reach sums to 20, such as 9+7, 9+8, 9+9, etc. and subtraction from the teens down. Such as 13-9, 12-9, 11-9.