Idea 11of 13Builds onDescribe the slide
Subtract to find the slide
Can you find a slide from the numbers alone, without counting squares?
Today you'll discover
- how subtracting gives the distance
- how to tell right from left
- how to tell up from down
Think firstP is at (3, 9). Q is at (10, 4).
From P to Q, how far across does the point slide?
Decide first, then press Next. Subtract, then ask which end was bigger.
A coordinate grid with P at (3, 9) and Q at (10, 4). An L-shaped arrow goes 7 right along a grid line, then 5 down to Q, and 'P to Q: 7 right, 5 down' is written beside the grid.
See the whole ideathe big idea and the key word, in one place
The big idea
Subtract the first numbers for across, and the second numbers for up or down.
On any scaleOn a grid counting by 5s, (10, 20) to (35, 5) is 25 right and 15 down. Subtracting works on every scale.
Easy to get wrongSubtract the smaller number from the bigger, then let the direction come from which end was bigger.
Key word
- difference
- how far apart two numbers are: the bigger take away the smaller
Ready to use it?
- Describe a slide from two points' coordinates, without a grid.