Lesson 0 of 14

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A pie chart divides a circle into slices. Workers at the same speed finish a job in some days.

Figure 1 — a circle shared out, and pairs that keep one product.

This is Part II, Chapter 3, Proportional Reasoning-2.

What you will learn

The whole turn — one circle stands for a whole set. Going round it once is 360°.
A slice — a group's own share of the turn.
Drawing one — count, share, angle, draw, and check that it closes.
Reading one — what a chart can, and cannot, tell you.
Two charts — the same picture, two very different totals.
One up, one down — two amounts whose product stays fixed. A product is the answer to a multiplication.
Which kind — direct, inverse, or neither.
At work — workers and days, speed and time.
Many terms — a ratio with three or more parts.
Sharing a whole — one whole cut into many parts.

Every lesson has a lab. Move the numbers and watch the chart, or the pair, change.