Learning goals: Teacher Facing Compare and contrast (orally and using other representations) different ways jewelry boxes could be packed inside larger shipping boxes. Determine which size shipping box is least expensive, and present (orally and in writing) a justification. Make simplifying assumptions and determine what information is needed to solve a problem about shipping costs. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 6.4 Dividing Fractions, Grade 6.