Big Ideas: Fractions can only be compared accurately if they refer to the same size whole.
This lesson builds on grade 3 work in which students partition shapes into parts with equal areas. They should already understand from grade 3 that a fraction 1/b as the quantity formed by 1 part when a whole is partitioned into b equal parts; and that a fraction a/b as the quantity formed by a parts of size 1/b. The task uses several visual models (candy bars, cakes, and pattern blocks) to show and explain that the size of the fraction changes as the size of the whole changes. This lesson builds towards the more advanced grade 4 work of comparing two fractions with different numerators and different denominators.
Vocabulary: fraction, whole, numerator, denominator, compare
Special Materials:
Pattern blocks
Lesson plan