Idea 6of 13Builds onTwo scales, and halfway
Lines without labels
What is a grid line worth when it has no number?
Today you'll discover
- how to share the jump between labels
- how to read a point on unlabelled lines
Think firstOnly every fifth line is labelled
The labels go 10, 20, 30 on every fifth line. What is each line worth?
Decide first, then press Next. Count the spaces between two labels.
A coordinate grid whose axes are labelled only every fifth line, 10, 20 and 30. Two points, U and V. Their coordinates appear in turn: U (14, 8) and V (26, 22).
See the whole ideathe big idea and the key word, in one place
The big idea
When only some lines are labelled, share the jump between labels across the spaces.
For exampleA ruler numbers only centimetres, but each small line is a millimetre: 1 cm shared by 10 spaces.
Easy to get wrongCount spaces, not lines, between two labels: 10 to 20 has 5 spaces.
Key word
- interval
- the amount from one grid line to the next
Ready to use it?
- Work out what unlabelled grid lines are worth.
- Read points on a grid that labels only some lines.