1 / 43

Where Does that Algebraic Equation Come From? Moving From Concrete Experience to Symbolic Form "

Where Does that Algebraic Equation Come From? Moving From Concrete Experience to Symbolic Form ". Jim Rubillo JRubillo@verizon.net. What is Algebra?. The intensive study of the last three letters of the alphabet. The Policy Dilemma. Algebra in Grade 7/8 or Algebra When Ready?.

ananda
Télécharger la présentation

Where Does that Algebraic Equation Come From? Moving From Concrete Experience to Symbolic Form "

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Where Does that Algebraic Equation Come From?Moving From Concrete Experience to Symbolic Form" Jim Rubillo JRubillo@verizon.net

  2. What is Algebra? The intensive study of the last three letters of the alphabet.

  3. The Policy Dilemma Algebra in Grade 7/8 or Algebra When Ready?

  4. Algebra When Ready Only when students exhibit demonstrable success with prerequisite skills—not at a prescribed grade level—should they focus explicitly and extensively on algebra, whether in a course titled Algebra 1 or within an integrated mathematics curriculum. Exposing students to such coursework before they are ready often leads to frustration, failure, and negative attitudes toward mathematics and learning. NCTM Position : Algebra: What, When, and for Whom (September 2011)

  5. Major Themes that Start in PreK and Go all the Way through Grade 12 • Exploring and extending patterns • Representing mathematical ideas with symbols and objects • Using mathematical models to represent quantitative relationships • Analyzing change in various contexts

  6. What We Know About Student Difficulties in Algebra • Lack of proficiency in proportionality (fractions, decimals, ratios, percent) • Understanding the equal sign (do something vs. equality, balance) • Using Variables (placeholder vs. changing value) • Making the transition from words (verbal or written) to symbols. • Understanding of function concept (rule or formula) • Lack of exposure to multiple representations (numbers, graphs, tables, symbols, etc.)

  7. What We Know About Student Difficulties in Algebra Understanding the equal sign (do something vs. equality, balance) 3 + 5 = or (3x + 5) – (x -3) = versus 4 + 6 = 6 + 4 or y + (-y) = 0 Using Variables (placeholder vs. changing value) 2x + 3 = 17 versus y = 3x2 – 19x - 14

  8. The Far Too Typical Experience! • Here is an equation: y = 3x + 4 • Make a table of x and y values using whole number values of x and then find the y values, • Plot the points on a Cartesian coordinate system. • Connect the points with a line. Opinion: In a student’s first experience, the equation should come last, not first.

  9. SHOW ME!

  10. Equations Arise From Physical Situations How many tiles are needed for Pile 5? ? Pile 1 Pile 2 Pile 3 Pile 4 Pile 5

  11. Piles of Tiles A table can help communicate the number of tiles that must be added to form each successive pile? (the recursive rule) ? Pile 1 Pile 2 Pile 3 Pile 4 Pile 5

  12. Piles of Tiles How many tiles in pile 457? ? Pile 1 Pile 2 Pile 3 Pile 4 Pile 5

  13. Piles of Tiles A table can help communicate the number of tiles that must be added to form each successive pile? (the recursive rule) ? Pile 1 Pile 2 Pile 3 Pile 4 Pile 5

  14. Piles of Tiles Physical objects can help find the explicit rule to determine the number of tiles in Pile N? Pile 1 Pile 2 Pile 3 Pile 4 3+13+3+1 3+3+3+13+3+3+3+1

  15. Piles of Tiles Tiles = 3n +1 For pile N = 457 Tiles = 3x457 + 1 Tiles = 1372

  16. Piles of Tiles Graphing the Information. Tiles = 3n +1 n = pile number

  17. Piles of Tiles The information can be visually analyzed.

  18. Piles of Tiles How is the change, add 3 tiles, from one pile to the next (recursive form) reflected in the graph? Explain. How is the term 3n and the value 1 (explicit form) reflected in the graph? Explain. Y = 3n + 1

  19. Piles of Tiles The recursive rule “Add 3 tiles” reflects the constant rate of change of the linear function. The 3n term of the explicit formula is the “repeated addition of ‘add 3’” Y = 3n + 1

  20. Piles of Tiles Tiles = 3n +1 What rule will tell the number of tiles needed for Pile N?

  21. Playing with the Four Basic Operations 1 + 1 = 1 – 1 = 1 × 1 = 1 ÷ 1 =_______ Total = 2 0 1 1 4

  22. Playing with the Four Basic Operations 2 + 2 = 2 – 2 = 2 × 2 = 2 ÷ 2 =_______ Total = 4 0 4 1 9

  23. Playing with the Four Basic Operations 3 + 3 = 3 – 3 = 3 × 3 = 3 ÷ 3 =_______ Total = 6 0 9 1 16

  24. Playing with the Four Basic Operations 4 + 4 = 4 – 4 = 4 × 4 = 4 ÷ 4 =_______ Total = 8 0 16 1 25

  25. Playing with the Four Basic Operations Willing to Predict?

  26. Playing with the Four Basic Operations Willing to Predict?

  27. Playing with the Four Basic Operations Willing to Generalize? n + n = n – n = n × n = n ÷ n =_______ Total = 2n 0 n2 1 _______________ n2 + 2n + 1 = (n + 1)2

  28. Equations Arise From Physical Situations What is the perimeter of shape 6?

  29. Find the Perimeter A table can help communicate the length of the sides that must be added to a shape to find the perimeter of the next shape? (the recursive rule)

  30. Find the Perimeter A table can help communicate the length of the sides that must be added to a shape to find the perimeter of the next shape? (the recursive rule)

  31. Find the Perimeter Can we find the perimeter of shape N without using the recursive rule? (the explicit rule) 2N + 2

  32. Equations Arise From Physical Situations What is the perimeter of shape 6?

  33. Find the Perimeter A table can help communicate the length of the sides that must be added to a shape to find the perimeter of the next shape? (the recursive rule)

  34. Find the Perimeter A table can help communicate the length of the sides that must be added to a shape to find the perimeter of the next shape? (the recursive rule)

  35. Find the Perimeter Can we find the perimeter of shape N without using the recursive rule? (the explicit rule) 5N + 1

  36. How many beams are needed to build a bridge of length n? Bridge of length 6

  37. How many beams are needed to build a bridge of length n? Bridge of length n B = n + 2n + (n - 1) B = 3n + (n - 1) B = 4 + 3(n – 1) + (n – 2) B = 4n – 1 where n is the length of the bridge and B is the number of beams needed

  38. Follow the Fold(s)

  39. Follow the Fold(s)

  40. What’s the Graph?

  41. Total Cost Table: Example 1 P E N C I L S ERASERS

  42. Total Cost Table Example 2 P E N C I L S ERASERS

  43. Multiple Representations The understanding of mathematics is advanced when concepts are explored in a variety of forms including symbols, graphs, tables, physical models, as well as spoken and written words.

More Related