Checking and securing understanding of drawing linear graphs | Maths

Starter quiz

Match each point to its correct coordinates.

A

⇔

(4, -2) ✓

B

⇔

(2, -4) ✓

C

⇔

(-2, -4) ✓

D

⇔

(-4, -2) ✓

E

⇔

(-4, 2) ✓

F

⇔

(-2, 4) ✓
In algebra, when you replace variables with values you call this ...

calculating

evaluating

expanding

substituting ✓

solving
This is a table of values for a linear equation, but there is an error. Which value is the error?

$y = 19$

$y = 14$

$y = 10$ ✓

$y = 4$

$y = -1$
You are given the linear equation $y=3x +4$ . When $x=2$ , $y$ is ______.

'10' ✓
You are given the linear rule $y= 5 - 2x$ . When $x=-4$ , $y$ is ______.

'13' ✓
Which of these could represent an $x$ -intercept?

(-2, 0) ✓

(0, -3)

(0, 6)

(4, 0) ✓

(5, -5)

Exit quiz

Which of these is the $x$ -intercept of the line $2x + 3y = 6$ ?

(0, 2)

(0, 3)

(2, 0)

(2, 3)

(3, 0) ✓
Which of these is the $y$ -intercept of the line $2x + 3y = 6$ ?

(0, 2) ✓

(0, 3)

(2, 0)

(2, 3)

(3, 0)
Which of these coordinates are on the line with equation $y = 10-3x$ ?

(-4, -2)

(-3, 19) ✓

(0, -3)

(1, 9)

(2, 4) ✓
Which of these is the correct graph for the line with equation $2x + y = 8$ ? Each square represents 1 unit on each axis.
Match each equation of a line to its key features.

$y = 10-8x$

⇔

gradient -8 and $y$ -intercept (0, 10) ✓

$y = 8x + 10$

⇔

gradient 8 and $y$ -intercept (0, 10) ✓

$y =10x - 8$

⇔

gradient 10 and $y$ -intercept (0, -8) ✓

$y = 8 - 10x$

⇔

gradient -10 and $y$ -intercept (0, 8) ✓

$y =8x - 10$

⇔

gradient 8 and $y$ -intercept (0, -10) ✓
The gradient of the line with equation $2y = 4x -6$ is ______.

'2' ✓

Worksheet

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Presentation

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Video

Lesson Details

Key learning points

It is possible to identify the gradient and y-intercept when the equation is written in the form y = mx + c
Linear equations can be rearranged in order to reveal the gradient and y-intercept.
By substituting in values for one variable, you can find a corresponding values for the other.
These pairs of values can be plotted to give the graph of the equation.

Common misconception

Only two pairs of coordinates are needed to plot a linear graph.

Whilst true, this can cause issues if one pair of coordinates is calculated incorrectly. Encourage pupils to check a third point to ensure they are correct.

Keywords

Linear - The relationship between two variables is linear if, when plotted on a pair of axes, a straight line is formed.
Gradient - The gradient is a measure of how steep a line is.
Intercept - An intercept is the coordinate where a line or curve meets a given axis.