混合数乘法建模:面积模型与交互式解法

混合数乘法建模:面积模型与交互式解法
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2022-11-18 23:46
这个范例演示了如何使用面积模型和交互式工具来展示混合数的乘法运算。核心数学概念包括混合数的乘法、分数与整数的结合以及面积模型的几何意义。作图要点涉及使用GeoGebra命令如Shuffle、Polygon、PointIn、Denominator、If等来构建混合数对和乘积。适合小学四年级至五年级的学生,用于理解混合数乘法的直观表示和计算过程。

GeoGebra 命令及参数

  1. Shuffle({{1 / 2, 3 / 4}, {3 / 4, 1 / 2}, {1 / 2, 2 / 3}, {2 / 3, 1 / 2}, {1 / 3, 1 / 2}, {1 / 2, 1 / 3}, {1 / 4, 3 / 5}, {3 / 5, 1 / 4}, {2 / 5, 1 / 3}, {1 / 3, 2 / 5}, {2 / 3, 3 / 4}, {3 / 4, 2 / 3}, {1 / 2, 3 / 5}, {3 / 5, 1 / 2}, {2 / 5, 1 / 4}, {1 / 4, 2 / 5}}) → fracPairs, {{0.6, 0.25}, {0.6666666666666666, 0.5}, {0.6, 0.5}, {0.5, 0.75}, {0.25, 0.6}, {0.75, 0.5}, {0.6666666666666666, 0.75}, {0.4, 0.25}, {0.5, 0.6666666666666666}, {0.25, 0.4}, {0.4, 0.3333333333333333}, {0.3333333333333333, 0.5}, {0.75, 0.6666666666666666}, {0.3333333333333333, 0.4}, {0.5, 0.6}, {0.5, 0.3333333333333333}}
  2. Shuffle({{1, 2}, {2, 1}, {1, 1}, {1, 2}, {3, 1}, {2, 3}, {1, 3}, {1, 1}, {2, 1}, {2, 2}, {1, 2}, {2, 1}, {1, 3}, {3, 1}, {2, 1}, {2, 2}}) → wholePairs, {{1, 2}, {3, 1}, {2, 2}, {1, 1}, {1, 2}, {1, 3}, {1, 3}, {1, 2}, {2, 1}, {3, 1}, {1, 1}, {2, 3}, {2, 1}, {2, 1}, {2, 1}, {2, 2}}
  3. Polygon({PAnchor + (1, -1), PAnchor + (5, -1), PAnchor + (5, -5), PAnchor + (1, -5)}) → moveArea
  4. PointIn(moveArea) → PMove
  5. Denominator(fracB) → denomB
  6. Denominator(fracA) → denomA
  7. If(showsolution, (numA, (-numB)), PMove) → PReference
  8. Numerator(fracA) → numerA
  9. Numerator(fracB) → numerB
  10. RemoveUndefined(Flatten[Sequence[Sequence[If[i ≥ (wholeA * denomA) ∨ j ≥ (wholeB * denomB), (i / denomA, ((-j)) / denomB) + PAnchor], i, 0, numCols - 1], j, 0, numRows - 1]]) → startPositions
  11. Flatten(Sequence[Sequence[(i / denomA, ((-j)) / denomB) + PAnchor2 + (((wholeA * wholeB) * (1 + spacer)), 0), i, 0, denomA - 1], j, 0, denomB - 1]) → endPositionTemplate
  12. Sequence(If[A ≤ numCompositeWholes, (denomA * denomB), ((fracAB * denomA) * denomB)], A, 1, numCompositeWholes + 1) → numBlocks
  13. Flatten(Sequence[Zip[Translate[A, ((K * (spacer + 1)), 0)], A, endPositionTemplate], K, 0, Length[numBlocks] - 1]) → endPositionsWithExtras
  14. Sequence(endPositionsWithExtras(A), A, 1, Sum[numBlocks]) → allEndPositions
  15. Polygon({PAnchor, (x(PAnchor), y(PReference)), PReference, (x(PReference), y(PAnchor))}) → studentArea
  16. Polygon({(0, 0), (1 / denomA, 0), (1 / denomA, -1 / denomB), (0, -1 / denomB)}) → smallBoxTemplate
  17. Zip(Translate[smallBoxTemplate, A], A, startPositions) → allSmallBoxes
  18. Flatten(Sequence[Sequence[(i, (-j)), i, 0, wholeA - 1], j, 0, wholeB - 1]) → startUnitPositions
  19. Polygon({(0, 0), (1, 0), (1, -1), (0, -1)}) → unitBoxTemplate
  20. Sequence(PAnchor2 + ((i * (1 + spacer)), 0), i, 0, (wholeA * wholeB) - 1) → unitEndPositions
  21. Zip(Translate[unitBoxTemplate, Vector[PAnchor, A]], A, startUnitPositions) → allUnitBoxes
  22. Sequence(Segment[(x(PAnchor) + A, y(PAnchor)), (x(PAnchor) + A, y(PCorner))], A, 0, x(PCorner), 1) → gridWholeVertical
  23. Sequence(Segment[(x(PCorner) - 1 + A, y(PCorner)), (x(PCorner) + A - 1, y(PAnchor) + If[x(PMove) < 1, -1, 0])], A, 0, 1, 1 / Denominator[fracA]) → gridPartsVertical
  24. Sequence(Segment[(x(PAnchor) + If[y(PMove) < -1, 0, 1], y(PCorner)) + (0, A), (x(PCorner), y(PCorner)) + (0, A)], A, 0, 1, 1 / Denominator[fracB]) → gridPartsHorizontal
  25. Zip(Translate[A, Vector[(sliderSoln * Vector[B, C])]], A, allSmallBoxes, B, startPositions, C, allEndPositions) → smallBoxes
  26. Zip(Translate[A, Vector[(sliderSoln * Vector[B, C])]], A, allUnitBoxes, B, startUnitPositions, C, unitEndPositions) → unitBoxes
  27. Sequence(Segment[(x(PAnchor), y(PCorner) + A), (x(PCorner), y(PCorner) + A)], A, y(PAnchor) - y(PCorner), 0, -1) → gridWholeHorizontal
  28. Midpoint(PAnchor, (x(PAnchor), y(PReference)) + (-1, 0)) → AnchorNum2
  29. Circle(SolnPoint, 0.2) → solnOutline
  30. circlePixels(PMove, 7 + (7 * pulsing), Corner[1], Corner[3], Corner[5]) → pulsingPoint

AI 绘图提示语参考

绘制一个面积模型,展示两个带分数的乘法过程。首先,随机选择两个带分数,例如1/2和3/4,然后绘制一个矩形区域,表示这两个带分数的乘积。接着,在矩形内绘制小方格,表示每个带分数的组成部分。最后,根据选定的带分数,调整小方格的位置,展示乘积的几何意义。
以上提示语为根据原始绘图命令整理而来,仅供参考。