Learning goals: Teacher Facing Compare and contrast (orally and in writing) vertical calculations and base-ten diagrams that represent adding and subtracting decimals. Explain (in words and through other representations) that adding and subtracting decimals requires combining digits that represent like base-ten units. Interpret and create diagrams that represent 10 like base-ten units being composed into 1 unit of higher place value, e.g., 10 tenths as 1 one, and comprehend the word “bundle” to refer to this concept. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 6.5 Arithmetic in Base Ten, Grade 6.