Statistics
KS2MA-Y4-D008
Interpreting and presenting discrete and continuous data using appropriate graphical methods including bar charts, time graphs, and tables; solving comparison, sum and difference problems.
National Curriculum context
In Year 4, statistics introduces continuous data and time graphs alongside the bar charts and tables of Year 3. The non-statutory guidance clarifies that pupils should understand the difference between discrete data (individual counts, shown as bar charts) and continuous data (measurements over time, shown as line graphs). Pupils solve comparison, sum and difference problems using information from graphs and tables. The introduction of line graphs to show how a quantity changes over time (e.g. temperature through the day) prepares pupils for the more complex data interpretation of Years 5 and 6. Pupils also practise choosing appropriate representations for their data.
1
Concepts
1
Clusters
1
Prerequisites
1
With difficulty levels
Lesson Clusters
Read, interpret and draw line graphs showing continuous data over time
practice CuratedOnly one concept in this domain. Time graphs (line graphs) introduce continuous data and are the Year 4 statistics focus, distinct from the discrete data work of Y2-Y3.
Teaching Suggestions (1)
Study units and activities that deliver concepts in this domain.
Statistics: Discrete and Continuous Data
Mathematics Practical ApplicationPedagogical rationale
Y4 introduces the distinction between discrete data (counted, separate values) and continuous data (measured, can take any value on a scale). This is a significant conceptual step because it determines which type of graph is appropriate. Time graphs (line graphs showing change over time) are introduced as the first representation of continuous data. Children must understand that the line between plotted points on a time graph represents real intermediate values, unlike a bar chart where the space between bars is meaningless.
Prerequisites
Concepts from other domains that pupils should know before this domain.
Concepts (1)
Time graphs and continuous data
skill AI DirectMA-Y4-C018
A time graph (line graph) shows how a quantity changes continuously over time, with time on the horizontal axis. The continuous line between plotted points implies values exist for all intermediate times. Pupils must read values from the graph, describe trends (rising, falling, constant) and calculate changes. Mastery means pupils can read and interpret a time graph accurately, describe the trend, and answer comparison and difference questions.
Teaching guidance
Use familiar real-world contexts: temperature through the day, plant growth over weeks, a car journey showing distance over time. Plot simple datasets (4-6 data points) and draw the line between them. Distinguish from bar charts (bar charts use bars for discrete categories; line graphs use a continuous line for values that change over time). Emphasise reading values between plotted points (interpolation) as a key feature of continuous graphs.
Common misconceptions
Pupils often try to draw bar charts for data that should be a line graph (not understanding the discrete/continuous distinction). They may read only the plotted points and not realise they can read values between them. Some pupils join points with a straight ruler between each pair correctly, but then interpret the joined-up shape as the 'answer' rather than as a visual representation of change.
Difficulty levels
Reading plotted points on a time graph and answering 'what was the value at time X?' questions.
Example task
This graph shows temperature over the day. What was the temperature at 12:00?
Model response: The temperature at 12:00 was 18°C. [Reads from the plotted point]
Reading values between plotted points (interpolation) and describing the overall trend of a time graph.
Example task
The graph shows temperature readings at 10:00 (14°C) and 12:00 (18°C). Estimate the temperature at 11:00.
Model response: About 16°C. The line goes up evenly between 14 and 18, so halfway (11:00) is about 16.
Interpreting time graphs to describe trends, calculate changes, and compare different data sets on the same graph.
Example task
Between which two hours did the temperature rise the fastest? How much did it rise in total from 8:00 to 16:00?
Model response: The temperature rose fastest between 10:00 and 12:00 (the line is steepest there — it went up 4°C in 2 hours). Total rise from 8:00 (10°C) to 16:00 (20°C) = 10°C.
CPA Stages
concrete
Collecting real continuous data (e.g. temperature readings every hour using a thermometer) and plotting physical data points on a large wall chart, connecting them with string
Transition: Child plots data points, connects them to show a trend, and reads values between plotted points by interpolating
pictorial
Drawing time graphs on paper with correctly labelled axes, plotting data points and drawing a continuous line, and answering questions by reading the graph
Transition: Child draws time graphs with correct scales and labels, reads values between plotted points, and describes trends (rising, falling, steady)
abstract
Interpreting time graphs from descriptions or partial information, predicting trends, and choosing between bar charts (discrete) and line graphs (continuous) for different data
Transition: Child interprets time graphs from verbal descriptions, predicts trends, and consistently selects the correct chart type for discrete vs continuous data
Delivery rationale
Upper primary maths (Y4) — most pupils at pictorial/abstract stage. AI can deliver with virtual representations.