Speed, density and pressure – Year 8 maths lesson

Lesson 33 of 35 in the Year 8 maths course

UK version. UK school years, UK spelling and pounds (£). · US Math Department

A complete 45-minute lesson for Year 8 (ages 12–13) that runs on this page – at school or at home. Every answer is marked straight away, with a worked explanation.

Time: 45 minutes + 20 min homework
Year: Year 8 (ages 12–13)
You need: Paper, a pencil and this page
Marked: Instantly, with explanations

For parents: how to use this lesson

You don't need to know this topic yourself. The lesson explains each step on screen, one tidy step at a time. Every answer is marked straight away with a worked explanation, so you never have to mark anything.

Read what your child will learn and the big ideas together.
Press Start the lesson below and sit with your child for the teaching and the worked examples (about 19 minutes).
Let them do the practice on their own. They choose Getting started, On track or Challenge – start on On track and move up after a few right in a row.
Finish with the exit ticket and the talk question: “Why does a car travelling at 60 km/h go 1 km every minute?”
Later that day or the next day: the homework (20 minutes), then a practice test.

Watch out for

Using 30 minutes as 0.3 hours. 30 minutes is half an hour: 0.5.
Multiplying when you should divide. Check the units: km/h means km ÷ h.

Tip for home: Work out average speed on a journey from the distance and time.

What your child will learn

We are learning to use compound measures such as speed, density and pressure.

Success looks like

I can use the speed formula.
I can use density and pressure.
I can convert units in compound measures.

Key words

speed: distance covered in a unit of time
density: mass of one unit of volume
pressure: force on one unit of area
rate: how much of one quantity per unit of another

What to have ready

Paper and a pencil
This page on a computer, tablet or phone
For the hands-on part: Time how long it takes to walk 100 m and work out your speed in metres per second.

The big ideas (for the adult)

A compound measure combines two measures: speed = distance ÷ time, density = mass ÷ volume, pressure = force ÷ area.

Rearrange the formula to find another part: distance = speed × time.

Check the units match: a speed in km/h needs time in hours, so 30 minutes is 0.5 hours.

The lesson, step by step

45 minutes in 5 parts
Part	Time	How it is checked
Starter: quick recall	5 min	Marked by Classfern
Teaching input	10 min	Not assessed, self-checked
Worked examples and guided practice	9 min	Not assessed, marked by Classfern
Independent practice	15 min	Marked by Classfern
Plenary and exit ticket	6 min	Marked by Classfern, self-checked

Starter, "your turn", practice and exit ticket are marked by Classfern. Worked examples and teaching are not assessed. The hands-on task and the reflection are self-assessed. Explanations in talk are judged by the parent and not recorded.

The lesson

It runs here on the page. No sign-up and no names – progress is kept only in this browser.

Homework and practice at home

20 minutes: 10 practice questions, 3 multiple-choice questions and 2 to remember from earlier work, then a short reflection. New questions every time, all marked instantly.

More practice

All Year 8 maths lessons and tests · Maths Department

More Year 8 maths lessons

Curriculum

National Curriculum for England, Year 8: “use compound units such as speed, unit pricing and density to solve problems”

GCSE subject content R11: “use compound units such as speed, rates of pay, unit pricing, density and pressure”

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Our lessons and questions are our own. They are not written or endorsed by any government department, testing agency or exam board.