Best Buys, Ratios, and Rates ― Addition and Subtraction of Fractions
商品資訊
定價
：NT$ 1500 元無庫存，下單後進貨(到貨天數約30-45天)
可得紅利積點：45 點
相關商品
商品簡介
作者簡介
商品簡介
Best Buys, Ratios, and Rates: Addition and Subtraction of Fractions is one of five units in the Contexts for Learning Mathematics' Investigating Fractions, Decimals, and Percents (4 - 6)
The focus of this unit is the development of equivalence of fractions, proportional reasoning, and rates. It begins with a comparison of the cost of cat food at two stores: Bob's Best Buys where it is on sale, $15 for 12 cans, and Maria's Pet Emporium where it is on sale, $23 for 20 cans. Several important ideas and representations develop as students explore this problem, among them finding ways to determine the cost of a common numbers of cans for comparison and the use of the ratio table to represent their proportional reasoning about the context. The development of the ratio table is further supported in the next investigation as students work to determine the cost of several different amounts of bird seed sold by weight. As the unit progresses, proportional reasoning is once again the focus as students develop recipes for a variety of containers, using the recipe of Maria's gourmet puppy snack mix.
In the second week the double number is introduced for computation as students investigate the readings on a farm truck's gas tank over the course of trips to several neighboring farms to pick up produce. A trip across the Pennsylvania Turnpike is also explored.
This unit also includes several minilessons for addition and subtraction of fractions. Strings of related problems are used initially using money and clock models. Double number lines are introduced later in the unit to enable students to develop generalizable, strategies for addition and subtraction. This model supports students to choose a common multiple (or factor) to work with as well as further opportunities to explore equivalent fractions.
Note: The context for this unit assumes that your students have had prior experience with fractions and their relationship to division with whole numbers. If this is not the case, you might find it helpful to first use the units Field Trips and Fund-Raisers.
To learn more visit http://www.contextsforlearning.com
作者簡介
Cathy Fosnot is a leading voice in mathematics education. She is Professor Emerita of Education at the City College of New York and the founder of Mathematics in the City, a national center for professional development located at the college. In 2007 she established New Perspectives on Learning to devote her time to speaking around the world, fostering school change through professional learning and support, and producing new resources and materials. Watch Cathy talk about the importance of context in math. Follow Cathy on Twitter @ctfosnotBill Jacob is a Professor of Mathematics at the University of California, Santa Barbara. In addition to his mathematical research, he develops and teaches courses for pre-service teachers. He is coauthor with Catherine Fosnot of Young Mathematicians at Work: Constructing Algebra and has been a collaborator with Mathematics in the City for twelve years.
您曾經瀏覽過的商品
購物須知
外文書商品之書封，為出版社提供之樣本。實際出貨商品，以出版社所提供之現有版本為主。部份書籍，因出版社供應狀況特殊，匯率將依實際狀況做調整。
無庫存之商品，在您完成訂單程序之後，將以空運的方式為你下單調貨。為了縮短等待的時間，建議您將外文書與其他商品分開下單，以獲得最快的取貨速度，平均調貨時間為1~2個月。
為了保護您的權益，「三民網路書店」提供會員七日商品鑑賞期(收到商品為起始日)。
若要辦理退貨，請在商品鑑賞期內寄回，且商品必須是全新狀態與完整包裝(商品、附件、發票、隨貨贈品等)否則恕不接受退貨。