page > Lesson Plans > Math
Real World > Apple
student will use estimation, calculation of percentages and subjective-reasoning
Resources: Teacher: One apple per student; one scale or
balance with weights per group; napkins. Students: paper and pencil.
Teacher Preparation: Wash apples.
- Have class discussion
about percentage and what students consider to be the edible part of
- Divide class into
cooperative learning groups.
- Hand out apples
- Have students estimate
what part or percentage of apple is edible.
- Instruct students
to weigh apples (and napkin) and record result on paper.
- Students eat their
apples, saving all uneaten parts on their napkin.
- Students should
then weigh the napkin holding the uneaten part of the apple.
- Students subtract
weight of uneaten part from whole weight to find weight of edible part.
- Students divide
edible weight by whole weight to find percentage.
- Have one person
from each group record the data from each person.
- One person from
each group shares with the class the data and examples of uneated parts
of apples, comparing the estimations with the actual results.
Teacher can combine this exercise with a discussion of the subjective
nature of a definition and how that influences a scientific procedure.