Students identify a whole and partition shapes, lengths, and collections into equal halves, thirds, and fourths, recognizing and naming one-half, one-third, and one-fourth. They represent these fractions with area, set, and number-line models, recognize the same fraction in different shapes, and understand that two halves, three thirds, or four fourths compose one whole. Students solve simple equal-sharing and missing-part problems and compare the unit fractions one-half, one-third, and one-fourth, understanding that more equal parts make smaller shares.