---
title: "Bar charts and time graphs"
description: "Interpret and present discrete and continuous data using appropriate graphical methods, including bar charts and time graphs"
canonical: https://lightmysky.com/learn/mathematics/bar-charts-and-time-graphs-mt_ChjMU2GDJa
source: https://lightmysky.com/learn/mathematics/bar-charts-and-time-graphs-mt_ChjMU2GDJa.md
retrieved: 2026-09-12
---

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# Bar charts and time graphs

Interpret and present discrete and continuous data using appropriate graphical methods, including bar charts and time graphs

Subject: Mathematics · Area: Data & Statistics · Ages 8 to 9
Page: https://lightmysky.com/learn/mathematics/bar-charts-and-time-graphs-mt_ChjMU2GDJa

## Ready when they can

- Read a time graph showing temperature changes over a day
- Present data about plant growth over weeks as a time graph
- Explain the difference between a bar chart (discrete) and a time graph (continuous)

## Lesson: Bar graphs

A bar chart uses bars to compare separate groups, like how many children like each colour. Each bar's height shows a number. Taller bars mean bigger numbers.

*(drawing: Blue's bar is the tallest, so blue got the most votes.)*

A time graph is different. It shows something changing over time, like the temperature during a day. Instead of separate bars, you draw a line that moves up and down as the number changes.

**Example.** A gardener measures her plant every week. Week 1 it is 2 cm, week 2 it is 5 cm, week 3 it is 9 cm. She draws a time graph with a line that climbs higher each week, showing the plant growing.

**Tip.** Ask yourself: are these separate groups, or is something changing over time? Separate groups, like favourite colours, need a bar chart. Change over time, like temperature or growth, needs a time graph.

**Recap.** Bar charts compare separate groups with bars, and time graphs show change over time with a connecting line.

## Practice

18 questions on this page, each with its working shown.

## Needs first

- [Scaled picture graphs and bar graphs](https://lightmysky.com/learn/mathematics/scaled-picture-graphs-and-bar-graphs-mt_r8XnXwRA6g)
- [Data collection and display vocabulary](https://lightmysky.com/learn/mathematics/data-collection-and-display-vocabulary-mt_u5HkSxZECM)

## Opens up

- [Statistical Analysis Vocabulary](https://lightmysky.com/learn/mathematics/statistical-analysis-vocabulary-mt_fmm-P17Vka)
- [Reading and comparing bar and line graphs](https://lightmysky.com/learn/mathematics/reading-and-comparing-bar-and-line-graphs-mt_H6LlpWgEYS)
- [Graphing seasonal weather data](https://lightmysky.com/learn/science/graphing-seasonal-weather-data-mt_NYsz6QgaaE)
- [Recording data with diagrams and graphs](https://lightmysky.com/learn/science/recording-data-with-diagrams-and-graphs-mt_rDjtmDogJr)
- [Tables, charts, and graphs](https://lightmysky.com/learn/science/tables-charts-and-graphs-mt_YHsUhi4Prc)