Give your little one the opportunity to dive deeper into addition with this add thousandths less than 1 with regrouping worksheet. When adding decimals on this worksheet, students align the decimal points and use zero as a placeholder. They must also regroup the numbers to determine the sum. In each problem, the numbers are laid out in the horizontal format. Students should try to use different strategies involving composing and decomposing numbers to solve these problems. This will help them develop flexibility and fluency.