Lesson 0 of 11

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3 min

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A shop card says 20% OFF. Off what?

Figure 1 — a percentage marks one point on a fixed 0-to-100 scale.

This track follows Part II, Chapter 1, Fractions in Disguise.

What you will learn

Out of a hundred — the second number is always 100.
Three names — a fraction, a decimal and a percentage.
Taking a percentage — how much is 15% of 200?
Finding a percentage — 18 out of 24 is what percentage?
Up and down — a rise or a fall is of the start. You can also find the start.
There and back — up 20%, then down 20%.
Comparing fairly — two groups, one fair number.
Where they are used — a target, a marked price, a total.

Every lesson has a lab. Move something and watch the percentage.