Times Table Chart - 2, 3, 4, 5, 6, 7, 8 & 9 / FREE Printable Worksheets ... Description This packet has 20 worksheets and 48 black and white task cards of Double digit Addition and Subtraction WITH and WITHOUT regrouping (mixed problems) For each problem, students will decide to regroup or not to regroup. Answer keys are included. Sheets are neatly formatted.