Give your little one the opportunity to dive deeper into addition and subtraction with this add and subtract 6-digit and 4-digit numbers without regrouping worksheet. Subtraction is the opposite operation of addition and vice versa. Students use this relationship and their understanding of basic addition and subtraction facts to add and subtract 6-digit and 4-digit numbers without regrouping in this worksheet. This worksheet is about practicing the column method in which numbers are written one on top of another. In this method, students use their place value understanding to solve the problems.