Topic 6 Year 8 Mathematics
Mathematics  
Topic  Direct and inverse Proportion  
No of lessons  12  
When is it happening  Term 2 Year 8  
What will students learn  This unit begins by looking at proportional relationships in familiar contexts building on their understanding of ratio from the previous unit. Students look at the meaning of direct proportion and make links to linear graphs from the last unit. Students will develop their proportional reasoning skills by solving a variety of problems. Students are encouraged to compare different approaches to solving problems involving direct proportion. In the second week of this unit, students will meet the concept of inverse proportion. Students will encounter different contexts where one variable increases, the other decreases, but their product remains constant. As a way into this, students are invited to make different rectangles with a constant area. The graphing of the side lengths will reveal an inversely proportional relationship. Students will use this understanding to solve problems involving inverse proportion.  
Key Knowledge that students should know at the end of 'Topic'  This is the knowledge that students will meet for the first time in this topic  relationships algebraically  
This is knowledge that students may have met before but will need to deepen their understanding  Proportional reasoning, different ways of defining ratio and proportion. multiplication, division, fractions, decimals and percentages, as well as a unit introducing the formal notation for ratio.  
Key Skills that students should be able to demonstrate at the end of 'Topic'  This is the skills that students will meet for the first time in this topic  Simplify, understand : means ratio  
This is skills that students may have met before but will need to develop  Using a scientific calculator  
Key vocabulary that students should know and understand  Proportion, Proportional  
The Big Question  It takes 4 friends 6 hours to clean a garden, how long will it take 2?  
Key questions that students should be able to answer at the end of the 'Topic'

What is direct proportion?  
What is the unitary method?  
If 4 pens cost 1.60 how much do 12 pens cost?  
How do you solve proportion problems?  
How do you solve money problems?  
How do you use a proportion graph?  
How do you solve a direct proportion problems?  
If four tickets cost £42 how much does 9 cost?  
What is inverse proportion?  
If it takes 2 people 3 hours to clean a house how long does it take 4?  
What does an inverse proportion graph look like?  
What is the difference between direct and inverse proportion? 