• On boards, draw a set of axes from -5 to 5 in both the x and y directions
• In your pairs, label yourselves A and B
• Person A needs to draw a line graph on their axes without showing
person B
• Now person A describes the line graph to person B, who draws the graph
from the description
• Once done, check that the two graphs match
• If they do, sketch the graph and description given on a piece of square
paper
• If they don’t, as a pair work out what went wrong, and sketch the
correct graph with a correct description on a piece of square paper
• Repeat the process, swapping roles.
What information do we need to
describe a line accurately?
The y-intercept and the gradient
Objective: To recognise and use the y-intercept
and the gradient of a graph.
Find the gradient and y-intercept of the straight-line graph.
(4,6)
8
(0,-2)
4
Find the gradient and y-intercept of the straight-line graph.
(-9,5)
18
-6
(9,-1)
In your own words,
write down a definition
of the y-intercept and
the gradient
If the line slopes up from left to right, then the gradient
is positive.
If the line slopes down from left to right, then the
gradient is negative.
• On boards, draw a set of axes from -5 to 5 in both the x and y directions
• In your pairs, label yourselves A and B
• Person A needs to draw a line graph on their axes without showing
person B
• Now person A describes the line graph to person B, who draws the graph
from the description
• Once done, check that the two graphs match
• If they do, sketch the graph and description given on a piece of square
paper
• If they don’t, as a pair work out what went wrong, and sketch the
correct graph with a correct description on a piece of square paper
• Repeat the process, swapping roles.
Draw two parallel lines.
What do you notice about the gradient
and y-intercept of these lines?
Is this always true?
Draw two perpendicular lines.
What do you notice about the gradient of
these lines?
Is this always true?