Quick Guess Estu’s notebook donation may benefit 100 to 200 students could benefit each year. Roxie’s meal offering is perhaps enough grains or meals to feed 150 to 300 people annually. Estimate and calculate Assumptions: Estu’s weight ~ 38 kg Cost of 1 notebook ~ ₹ 20 Roxie’s weight is ~ 45 kg Cost of 1 kg of grain or meal donations ~ ₹ 30 Meal cost per person per day ~ ₹ 15 Estu’s donation: Notebooks worth her weight Value of donation = 38 × ₹ 20 = ₹ 760 If each student needs 2 notebooks: No. of students helped = ₹ 760 ÷ ₹ 40 = 19 19 students could receive notebooks each year. Roxie’s donation: Grains or Meals worth her weight Value of donation = 45 × ₹ 30 = ₹ 1350 Each meal costs = ₹ 15 ∴ No. of people to whom meal can be provided = ₹ 1350 ÷ 15 = 90 90 people could receive a single meal, or fewer people could eat multiple meals per year.