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, students practice solving problems written in the horizontal format. How numbers are laid out in a problem affects the method a student employs to solve it. Therefore to develop actual fluency and mastery of multiple strategies, students must practice different formats.