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← Proportional Reasoning-2

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Lesson 5 of 14

Two charts that look the same

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8 min

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One class of 40 voted. A school of 200 voted the same way. Each game's share of voters is the same in both. Draw both charts.

Left chart: a class of 40.
Step 1 of 4
  1. Left chart: a class of 40.
  2. Right chart: a school of 200, same angles.
  3. Same angles, both sides.
  4. Only the totals differ: 40 and 200.

Every count on the right is five times the left. That is because 200 is five times 40. Cricket: 15 becomes 75. Kabaddi: 10 becomes 50.

In the class, one voter is 9°. In the school, one voter is 1.8°. Cricket: 15 × 9° = 135° and 75 × 1.8° = 135°. Kabaddi: 10 × 9° = 90° and 50 × 1.8° = 90°.

Rule: Multiply every count by the same number. Every share stays exactly the same.

Drag the slider to change the cricket voters on the right. Watch the angle.

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