Fraction Multiplication Demo by Robert Fant

Fraction Multiplication Demo by Robert Fant
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2017-09-22 01:42
This example dynamically demonstrates the multiplication of two fractions, visually showing the geometric meaning of fraction multiplication. It involves core math concepts like fraction multiplication rules, area relationships in geometric figures (e.g., parallelograms), and basic ideas of probability and distributions. Construction highlights include commands/objects like Point, Polygon, Textfield, IndexOf, Take, Sequence, RemoveUndefined, Intersection, GCD, and elements such as mover, f2Point, f1Point, f1, f1poly, etc., creating a visual model for fraction multiplication. Suitable for middle school and above learners to understand the essence and geometric applications of fraction multiplication.

GeoGebra Commands & Parameters

  1. Point({1 - mover, 0}) → f2Point
  2. Point({-1 + mover, 0}) → f1Point
  3. Polygon(f1Point, f1Point + (f1, 0), f1Point + (f1, 1), f1Point + (0, 1)) → f1poly, f1point, n, p, q
  4. Polygon(f2Point, E, G, H) → poly3, f2point, e, g_1, h_1
  5. Textfield(f1Text) → InputBox1
  6. Textfield(f2Text) → InputBox2
  7. IndexOf(47, TextToUnicode[f1Text]) → slash1
  8. IndexOf(47, TextToUnicode[f2Text]) → slash2
  9. Take(f1Text, slash1 + 1) → D1Text
  10. Polygon(f1Point, f1Point + (1, 0), 4) → poly1, f, g, h, i, A, B
  11. Polygon(f2Point, f2Point + (1, 0), 4) → poly2, j, k, l, m, C, D
  12. Take(f2Text, slash2 + 1) → D2Text
  13. Sequence(Segment[f1Point + (i / D1, 0), f1Point + (i / D1, 1)], i, 1, D1 - 1) → f1Bars
  14. Sequence(Segment[f2Point + (0, i / D2), f2Point + (1, i / D2)], i, 1, D2 - 1) → f2Bars
  15. Polygon(f2Point, f2Point + (0, f2), f2Point + (1, f2), f2Point + (1, 0)) → f2poly, r, s, t, a
  16. RemoveUndefined(Sequence[If[pN / i ≟ floor(pN / i), i], i, 1, pN]) → Nfactors
  17. RemoveUndefined(Sequence[If[pD / i ≟ floor(pD / i), i], i, 1, pD]) → Dfactors
  18. Intersection(Nfactors, Dfactors) → factors
  19. GCD(N3, D3) → GCD