Grade 3 math worksheet - Addition: adding 3-digit numbers in columns ... Worksheets Math Grade 3 Addition 3-digit numbers in columns Adding 3-digit numbers in columns (with regrouping) 3-digit numbers, with regrouping These column form addition questions feature 3-digit numbers (<1,000); worksheet solutions do require regrouping or borrowing. Worksheet #1 Worksheet #2 Worksheet #3 Worksheet #4 Worksheet #5 Worksheet #6