My approach to decimals is connected very explicitly to the work I do developing multi digit number with a focus on multiplicative reasoning. Array models provide a visual support that allows students to see NUMBER is in NUMBER. This is a critical understanding for making sense of decimal fractions.
Develop decimal number sense by connecting the imagery of the area model to the imagery of the number line. Compare decimal fractions using words, fraction notation and decimal notation. Build imagery through words and pictures before going to manipulating symbols. When students understand, they do not need misconceptions like “lining up” to add or subtract.
Here are the BERCS CARDS for Decimals: