Children use their math skills to complete this add and subtract hundredths and thousandths worksheet. When adding or subtracting decimals, students line up the decimal points and add extra zeros to the right of the number so that each decimal has the same number of digits. Students then add or subtract digits at each place to find the answer. In this worksheet, numbers are laid one on top of another (vertical format). This encourages students to use the inherent place value structure to solve the problems.