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Explore various models and methods to teach fractions, from part-whole to length and set models, emphasizing understanding over rote memorization.
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Fraction Meanings EDN 322
Students should be given the opportunity to develop concepts as well as number sense with fractions and decimals. NCTM (2000)
North Carolina Standard Course of Study • Kindergarten1.02 Share equally (divide) between two people; explain. • First Grade 1.04 Create, model, and solve problems that use addition, subtraction, and fair shares (between two or three).
North Carolina Standard Course of Study • Second Grade 1.02 Use area or region models and set models of fractions to explore part-whole relationships in contexts. 1.03 Create, model, and solve problems that involve addition, subtraction, equal grouping, and division into halves, thirds, and fourths (record in fraction form). • Third Grade 1.05 Use area or region models and set models of fractions to explore part-whole relationships.
North Carolina Standard Course of Study • Fourth Grade 1.03 Solve problems using models, diagrams, and reasoning about fractions and relationships among fractions involving halves, fourths, eighths, thirds, sixths, twelfths, fifths, tenths, hundredths, and mixed numbers. • Fifth Grade 1.02 Develop fluency in adding and subtracting non-negative rational numbers (halves, fourths, eighths; thirds, sixths, twelfths; fifths, tenths, hundredths, thousandths; mixed numbers).
Cookies to Share • Does this teacher accomplish NCTM’s goal of developing concepts as well as number sense with fractions? • Are the NCTM process standards covered in this lesson? • Other observations? (use of materials, etc.)
Three Meanings of Fractions 1. Part-Whole 2. Quotient 3. Ratio • Region • Length • Set • Area
The Region Model What fraction of the rectangle is purple? 2 6
The Region Model What fraction of the pie is purple? 3 4
The Whole 15 Marbles Partitioned into 5 equal parts: Each part is one-fifth. Two parts are two-fifths. Three parts are three-fifths. Four parts are four-fifths. Five parts are five-fifths or the whole.
The Set Model What fraction of the musical instruments have strings? 2 5
3 5 The Set Model What fraction of the fish have stripes?