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Content Session 2. July 8, 2009. In a recent basketball game, Diana made 6 of 8 free throws in the first half. In the second half, she made 8 of 10 free throws. What fraction of free throws did Diana make in the first half? What fraction of free throws did she make in the second half?
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Content Session 2 July 8, 2009
In a recent basketball game, Diana made 6 of 8 free throws in the first half. In the second half, she made 8 of 10 free throws. • What fraction of free throws did Diana make in the first half? • What fraction of free throws did she make in the second half? • What fraction of free throws did she make in the whole game?
A 5th grader announces, “See, we can just add the numerators and the denominators together to add fractions!”
Fractions are difficult in part because there are different meaning / interpretations of fractions. To understand fractions means, in part, to be able to freely move across these different meaning.
What is a fraction? • Part of a whole • M1N4 c: Identify, label, and relate fractions (halves, fourths) as equal parts of a collection of objects or a whole using pictures and models. • M2N4 a. Model, identify, label, and compare fractions (thirds, sixths, eighths, tenths) as a representation of equal parts of a whole or of a set. b. Know that when all fractional parts are included, such as three thirds, the result is equal to the whole.
What is a fraction? • Measures • M3N5 c. Understand the fraction a/b represents a equal sized parts of a whole that is divided into b equal sized parts. d. Know and use decimal fractions and common fractions to represent the size of parts created by equal divisions of a whole.
What is a fraction? • Quotient • M5N4 a. Understand division of whole numbers can be represented as a fraction (a/b= a ÷ b).
Another reason fractions are difficult: • A single number may be labeled with multiple fractions • Which form of fraction is appropriate depends on the context • Grade 4: being aware some fractions represent the same number • Grade 5: being able to create equivalent fractions
Decimal Numbers • Another form of representing fractions with powers of 10 as the denominators • Extension of the decimal numeration system
Unitary Perspective of Numbers • 30 is 3 tens • 30000 is 3 ten-thousands • 3/5 is 3 1/5-units • 3/8 is 3 1/8-units • 0.3 is 3 0.1-units • 0.003 is 3 0.001-units
Representing Fractions & Decimal Numbers • Number Lines: different kinds of numbers (whole numbers, fractions, and decimal numbers) can be represented on the same model • The National Math Panel recommends an increased attention on number lines (with fractions).
Show ¾ using: • Pattern blocks • Cuisenaire rods • Connecting cubes
What’s wrong (if any)? • The green piece shows 1/3.
Three Common Attributes • Area • Length • Counts