3 DIGIT ADDITION (REGROUPING UNITS AND TENS) / Grade 4 Math / By worksheetspack Sharing is Caring The students will improve their addition skills with these regrouping units and tens worksheets. A group of 10 units can be regrouped to make 1 ten and a group of 10 tens can be regrouped to make 1 hundred. Free worksheets Download Let’s practice more with these addition worksheets.