Learning goals: Teacher Facing Add or subtract decimals, and explain the reasoning (using words and other representations). Comprehend the term “unbundle” means to decompose a larger base-ten unit into 10 units of lower place value (e.g., 1 tenth as 10 hundredths). Recognize and explain (orally) that writing additional zeros or removing zeros after the last non-zero digit in a decimal does not change its value. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 6.5 Arithmetic in Base Ten, Grade 6.