Averages and range – Year 8 maths lesson
Lesson 17 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: “When is the median a better average than the mean?”
- Later that day or the next day: the homework (20 minutes), then a practice test.
Watch out for
- Finding the median without putting the data in order. Order the values first, then find the middle.
- Giving the frequency as the mode. The mode is the value, not how many times it appears.
Tip for home: Find the average of a week's temperatures or bus journey times.
What your child will learn
We are learning to find the mean, median, mode and range and choose the best average.
Success looks like
- I can find the mean, median and mode.
- I can find the range.
- I can choose the best average.
Key words
- mean
- total ÷ number of values
- median
- the middle value in order
- mode
- the most common value
- range
- largest minus smallest
What to have ready
- Paper and a pencil
- This page on a computer, tablet or phone
- For the hands-on part: Collect the heights or ages of family members and find all three averages.
The big ideas (for the adult)
The mean is the total divided by how many values. The median is the middle value when the data is in order. The mode is the most common value.
The range is the largest value minus the smallest: it shows how spread out the data is.
An extreme value (an outlier) pulls the mean, so the median can be a better average.
The lesson, step by step
| 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
More Year 8 maths lessons
- Ordering numbers, decimals and negatives
- Calculating with negative numbers
- Prime factors, HCF and LCM
- Rounding and estimation
- Powers and roots
- Written methods with decimals
- BIDMAS: order of operations
- Calculating with fractions
- Units and measures
- Area of triangles, parallelograms and trapeziums
- Circles: circumference, area, arcs and sectors
- Angle facts and parallel lines
- Angles in polygons
- Transformations
- Quadrilaterals and symmetry
- Constructions and loci
- Scatter graphs and correlation
- Probability
- Relative frequency and expected outcomes
- Algebraic notation
- Substitution
- Simplifying expressions
- Expanding brackets
- Solving linear equations
- Sequences and the nth term
- Straight-line graphs
- Graphs of functions
- Ratio
- One quantity as a fraction or percentage of another
- Percentages
- Direct and inverse proportion
- Speed, density and pressure
- Best buys and exchange rates
- Scale drawings and maps
Curriculum
National Curriculum for England, Year 8: “describe, interpret and compare observed distributions of a single variable through: appropriate graphical representation involving discrete, continuous and grouped data; and appropriate measures of central tendency (mean, mode, median) and spread (range, consideration of outliers)”
GCSE subject content S4: “interpret, analyse and compare the distributions of data sets from univariate empirical distributions through: appropriate graphical representation involving discrete, continuous and grouped data, including box plots; appropriate measures of central tendency (median, mean, mode and modal class) and spread (range, including consideration of outliers, quartiles and inter-quartile range)”
Contains public sector information licensed under the Open Government Licence v3.0.
Our lessons and questions are our own. They are not written or endorsed by any government department, testing agency or exam board.