Mean Averages: Calculate and Work Backwards
Year 6 Mathematics Learning to find and use mean averages
What is the Mean Average?
The mean is the most common type of average It tells us the typical value in a set of numbers We use it to understand data better Also called the arithmetic mean
How Do We Calculate the Mean?
Step 1: Add up all the numbers Step 2: Count how many numbers there are Step 3: Divide the total by the count This gives us the mean average
The Mean Formula
Mean = Sum of all values ÷ Number of values
Let's Calculate a Mean!
Find the mean of these test scores: 8, 6, 9, 7, 5 Work with a partner Show your working
Working Backwards with the Mean
Sometimes we know the mean but need to find a missing value We can rearrange our formula to help us This is called 'working backwards' Very useful for solving problems
Working Backwards Formula
Missing value = (Mean × Number of values) - Sum of known values
Working Backwards Challenge
Sarah's test scores are: 7, 8, 6, ? Her mean score is 7 What was her fourth test score? Use the working backwards formula
Quick Check Understanding
Why might we need to work backwards with means? Can you think of a real-life example? What's the most important step in calculating means?
Summary: Mean Averages
Mean = Sum ÷ Count Working backwards: find missing values when you know the mean Always check your answer makes sense Practice makes perfect!