Grows with count

Challenge 14 of 16

This is where it earns its keep. count is a plain number and the size is worked out from it, so changing that one number resizes the whole circle. Each count makes it 30 bigger.

Set count so the circle is 120 across.

Your code JavaScript

Set count so the circle is 120 across.

Console print() output

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Lesson Multiplying and Dividing

Multiplying uses a star and dividing uses a slash: var x = 5 * 4; makes 20, and var x = 20 / 4; makes 5. The line is the same shape as adding and taking away — only the sign in the middle changes.

A times is really a shortcut for adding the same number over and over. 4 * 3 is 4 + 4 + 4. Once you see that, multiplying stops being a new idea and becomes a quicker way of writing an old one.

Order does not matter for a times, the way it did not for adding: 3 * 5 and 5 * 3 both make 15. It does matter for a share, like taking away — 20 / 4 is 5, but 4 / 20 is not.

Sharing has one wrinkle. It does not always come out even. 24 / 4 is 6, but 24 / 5 is 4.8 — a number with a decimal point. Nothing is broken when that happens, but in this course the numbers are meant to be whole, so it usually means the two numbers are not a tidy pair.

The second half of this topic does something new: a box can size a shape, not just print a number. circle(200, 200, size); makes the circle as wide as whatever is in size, and if that size is worked out — var size = count * 30; — then changing one small number resizes the whole picture. That is the real reason for all of this.

A last note: a size on screen cannot be judged to the pixel, so where a challenge needs an exact one it tells you the number to aim for.