Myths about teaching can hold you back
- Year 10•
- Foundation
Checking and understanding graphs showing direct proportion
I can recognise direct proportion graphically and can interpret graphs that illustrate direct proportion.
- Year 10•
- Foundation
Checking and understanding graphs showing direct proportion
I can recognise direct proportion graphically and can interpret graphs that illustrate direct proportion.
Lesson details
Key learning points
- Direct proportion can be recognised graphically.
- The equation of a direct proportion graph is of the form y = kx
- The origin is always a point on a direct proportion graph.
- The gradient tells us the constant of proportionality.
Keywords
Direct proportion - Two variables are in direct proportion if they have a constant multiplicative relationship.
Common misconception
Direct proportion can be determined by calculating the gradient.
The equation of the line should be of the form y = kx and so the y-intercept should be calculated to check it is zero.
To help you plan your year 10 maths lesson on: Checking and understanding graphs showing direct proportion, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 10 maths lesson on: Checking and understanding graphs showing direct proportion, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 maths lessons from the Linear graphs unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Prior knowledge starter quiz
6 Questions
Q1.If two variables share a constant multiplicative relationship they are in direct to one another.
Q2.In this example how can you tell that the variables $$x$$ and $$y$$ are not in direct proportion?

Q3.The cost of hiring headphones at a festival is directly proportional to the time you hire them for. If two hours cost £16, how much should five hours cost?
Q4.The gradient of a straight line that passes through coordinates (10, 18) and (17, 53) is
Q5.What is the equation of this line?

Q6.Find the equation of the straight line that goes through coordinates (8, -1) and (12, 1).
Assessment exit quiz
6 Questions
Q1.Graphs of direct proportion intersect the axes at the .
Q2.Graphs of direct proportion begin at the origin and ...
Q3.Select the graphs that represent direct proportion.




Q4.For the coordinates (8, 20) and (10, 25), $$x$$ and $$y$$ are in direct proportion. Which of these coordinates also represent this same direct proportion?
Q5.The point P lies on this direct proportion graph. The $$y$$-coordinate of P is $$25$$, the $$x$$-coordinate of P is .

Q6.The point P lies on this direct proportion graph. The $$x$$-coordinate of P is $$375$$. Which of these calculations can you use to find the $$y$$-coordinate of P?
