Data Handling β€” Line Graphs, Pie Charts

Mathematics

Class 5 | CBSE, NCERT & ICSE

Learning Objectives

Introduction β€” Data is Everywhere!

Every day, we come across information in the form of numbers. The marks you score in tests, the temperature outside your house each morning, the runs scored by India in each over of a cricket match, the number of students absent in your class every day β€” all of this is data.

But raw numbers alone can be confusing. Imagine your teacher lists the marks of 40 students in one long row β€” it would be hard to make sense of it! That is why we organise data into tables, and then represent it using graphs and charts. Graphs turn numbers into pictures, making it easy to compare, spot trends, and draw conclusions at a glance.

In Class 5, we will learn four types of data representation: Pictographs, Bar Graphs, Line Graphs, and Pie Charts. You will also learn when to use each type and how to read them like a pro!

What is Data?

Data is a collection of facts, numbers, or information gathered for a specific purpose. Data can be about anything β€” heights of students, favourite colours, number of cars passing a road, temperatures over a week, pocket money received, etc.

Raw Data vs Organised Data

Raw data is the information as it is collected, without any arrangement. For example, the marks of 10 students written randomly:

Raw data (marks out of 50): 45, 32, 38, 45, 50, 32, 40, 38, 45, 50

This is hard to read. We need to organise it.

Frequency Table (Tally Marks)

A frequency table shows how many times each value appears. We use tally marks to count: each stroke (|) = 1, and every 5th stroke crosses the previous four (||||).

MarksTally MarksFrequency
32||2
38||2
40|1
45|||3
50||2

Now we can clearly see that 45 marks appeared most often (3 times). The frequency tells us how many times a particular value occurs in the data.

Think About It: Why do we cross every 5th tally mark? It makes counting easier! Instead of counting individual strokes, we can count in groups of 5.

Pictograph β€” Pictures Tell a Story

A pictograph uses pictures or symbols to represent data. Each picture stands for a certain number of items. This number is called the key or legend.

How to Read a Pictograph

  • Look at the key β€” it tells you what each picture represents (e.g., 🍎 = 5 students)
  • Count the pictures in each row or column
  • Multiply the number of pictures by the key value
  • A half picture means half the key value
Example: The pictograph below shows the favourite fruits of students in Class 5-A.
Key: 🍎 = 4 students
FruitNumber of StudentsTotal
Mango🍎🍎🍎🍎4 Γ— 4 = 16
Apple🍎🍎🍎3 Γ— 4 = 12
Banana🍎🍎2 Γ— 4 = 8
Guava🍎🍎½2Β½ Γ— 4 = 10
Orange🍎🍎🍎½3Β½ Γ— 4 = 14

Questions:

  • Which fruit is liked by the most students? β†’ Mango (16 students)
  • How many more students like Mango than Banana? β†’ 16 βˆ’ 8 = 8 students
  • Total students surveyed? β†’ 16 + 12 + 8 + 10 + 14 = 60 students
Image needed: A colourful pictograph showing favourite fruits (Mango, Apple, Banana, Guava, Orange) using fruit icons. Key shows 1 fruit icon = 4 students. Labels clear and child-friendly. Title: "Favourite Fruits of Class 5-A".
Style: Flat illustration, bright colours, grid layout, clear legend at bottom
Size: 700Γ—400px
Example 2 (Indian Context): A pictograph shows vehicles passing a school gate in one hour.
Key: πŸš— = 10 vehicles
VehicleSymbolsNumber
Auto-rickshawπŸš—πŸš—πŸš—πŸš—πŸš—50
CarπŸš—πŸš—πŸš—30
Two-wheelerπŸš—πŸš—πŸš—πŸš—πŸš—πŸš—πŸš—70
BusπŸš—πŸš—20
BicycleπŸš—πŸš—πŸš—πŸš—40

Total vehicles: 50 + 30 + 70 + 20 + 40 = 210 vehicles

Bar Graph β€” Comparing with Bars

A bar graph uses rectangular bars of equal width to represent data. The length (or height) of each bar shows the value it represents. Bars can be drawn vertically (standing up) or horizontally (lying flat).

Parts of a Bar Graph

  • Title: Tells what the graph is about
  • X-axis (horizontal): Shows the categories (e.g., subjects, months, items)
  • Y-axis (vertical): Shows the values/numbers with a scale
  • Scale: The number each unit on the axis represents (e.g., 1 unit = 5 students)
  • Bars: Rectangles of equal width, with height showing the value
  • Gap: Equal spacing between bars
Example 1: Marks scored by Arjun in different subjects (out of 100):
SubjectMarks
Maths85
Science78
English92
Hindi70
Social Studies65

To draw a vertical bar graph:

  • X-axis: Subject names
  • Y-axis: Marks (scale: 1 unit = 10 marks, going from 0 to 100)
  • Draw bars of height 85, 78, 92, 70, and 65 for each subject

From the graph we can tell:

  • Arjun scored highest in English (92)
  • He scored lowest in Social Studies (65)
  • Difference between highest and lowest = 92 βˆ’ 65 = 27 marks
Image needed: A vertical bar graph titled "Marks Scored by Arjun" with X-axis showing subjects (Maths, Science, English, Hindi, Social Studies) and Y-axis showing marks 0-100. Bars coloured differently. Grid lines visible. Scale clearly labelled.
Style: Clean flat illustration, colourful bars (one colour per subject), grid background, child-friendly
Size: 700Γ—450px
Example 2 (Horizontal Bar Graph): Favourite sports of students in Class 5-B:
SportNumber of Students
Cricket18
Football12
Badminton8
Kabaddi6
Swimming4
Hockey7

In a horizontal bar graph, the categories go on the Y-axis and the values go on the X-axis. The bars extend to the right.

How to Draw a Bar Graph (Step by Step)

Steps to Draw a Bar Graph

  • Step 1: Draw two perpendicular lines (axes) β€” the X-axis and Y-axis
  • Step 2: Choose a suitable scale (e.g., 1 cm = 5 students)
  • Step 3: Write category names on one axis and number scale on the other
  • Step 4: Draw bars of equal width with proper height according to the data
  • Step 5: Keep equal gaps between bars
  • Step 6: Give your graph a title and label both axes
Think About It: Why do bar graphs need equal gaps between bars? Because the gaps make it clear that each bar represents a separate category. Without gaps, it would look like the bars are connected β€” which is what a histogram does (a topic for higher classes)!

Line Graph β€” Showing Change Over Time

A line graph uses points connected by straight lines to show how data changes over time. It is the best graph to use when you want to see trends β€” whether something is increasing, decreasing, or staying the same.

When to Use a Line Graph

  • When data changes over time (hours, days, weeks, months, years)
  • When you want to see if values are going up or down
  • Examples: temperature over a week, plant height over days, cricket score over overs, COVID cases over months

Parts of a Line Graph

Example 1: Temperature in Delhi over one week (in Β°C):
DayMonTueWedThuFriSatSun
Temp (Β°C)32343533302831

To draw this line graph:

  • X-axis: Days of the week (Mon to Sun)
  • Y-axis: Temperature in Β°C (scale: start from 25, go up to 40; 1 unit = 1Β°C)
  • Plot a point above each day at the correct temperature
  • Connect the points with straight lines

What the graph tells us:

  • Temperature was highest on Wednesday (35Β°C)
  • Temperature was lowest on Saturday (28Β°C)
  • Temperature rose from Monday to Wednesday, then fell till Saturday, and rose again on Sunday
  • Range = 35 βˆ’ 28 = 7Β°C
Image needed: A line graph titled "Temperature in Delhi (One Week)" with X-axis showing days Mon-Sun and Y-axis showing temperature 25Β°C-40Β°C. Points plotted at 32, 34, 35, 33, 30, 28, 31 and connected with lines. Grid lines visible. Rise and fall clearly shown.
Style: Clean flat illustration, blue/red line on white grid, dot markers at each point, child-friendly labels
Size: 700Γ—450px
Example 2: Height of a plant (in cm) measured every 5 days:
DayDay 5Day 10Day 15Day 20Day 25Day 30
Height (cm)3610151820

Observations from the line graph:

  • The plant grew continuously β€” the line goes up throughout
  • The plant grew fastest between Day 10 and Day 20 (steepest part of the line)
  • Growth slowed down after Day 25 (line becomes flatter)
  • Total growth = 20 βˆ’ 3 = 17 cm in 25 days
Example 3 (Cricket): India's score in a T20 match (runs scored in each over):
Over12345678910
Total Runs8152835425560728598

A line graph of this data shows how India's total score built up over the innings. A steep upward line means a lot of runs were scored in that over. A flat section would mean few runs.

How to Plot a Line Graph (Step by Step)

Steps to Draw a Line Graph

  • Step 1: Draw the X-axis (horizontal) and Y-axis (vertical)
  • Step 2: Write the time values on the X-axis (days, months, etc.)
  • Step 3: Choose a scale for the Y-axis and mark the values
  • Step 4: Plot each data point as a dot at the intersection of its X and Y values
  • Step 5: Connect the dots with straight lines (left to right)
  • Step 6: Give a title and label both axes
Think About It: A line going upward means the value is increasing. A line going downward means it is decreasing. A flat (horizontal) line means no change. The steeper the line, the faster the change!

Pie Chart (Circle Graph) β€” Parts of a Whole

A pie chart (also called a circle graph) is a circular diagram divided into slices. Each slice represents a part of the whole. The whole circle = 100% (or the total of all data). Pie charts are best for showing how a total is divided into different parts.

Key Facts About Pie Charts

  • The whole circle represents the total (100%)
  • Each slice shows a fraction or percentage of the total
  • Bigger slices mean larger portions of the total
  • All slices together must add up to 100%
  • Pie charts are good for showing how something is divided or shared
Example 1: How Meena spends her day (24 hours):
ActivityHoursPercentage
Sleeping833%
School729%
Homework/Study313%
Playing28%
Eating + Getting Ready28%
TV/Screen Time14%
Other Activities14%
Total24~100%

In the pie chart, the "Sleeping" slice would be the largest (33%), and "TV/Screen Time" and "Other" would be the smallest slices (4% each).

Image needed: A pie chart titled "How Meena Spends Her Day" with colourful slices for Sleeping (33%, blue), School (29%, green), Homework (13%, yellow), Playing (8%, orange), Eating (8%, pink), TV (4%, purple), Other (4%, grey). Each slice labelled with activity name and percentage. Legend shown.
Style: Bright flat colours, clean labels, child-friendly, clear legend
Size: 600Γ—500px
Example 2: Monthly family budget of Ravi's family (β‚Ή40,000 total):
ExpenseAmount (β‚Ή)Percentage
Food & Groceries12,00030%
Rent10,00025%
Education6,00015%
Transport4,00010%
Medical2,0005%
Savings4,00010%
Entertainment & Other2,0005%
Totalβ‚Ή40,000100%

Reading the pie chart:

  • Which is the largest expense? β†’ Food & Groceries (30%)
  • What fraction of the budget goes to education? β†’ 15% = 15/100 = 3/20
  • How much is spent on rent and transport combined? β†’ β‚Ή10,000 + β‚Ή4,000 = β‚Ή14,000 (35%)

Calculating Values from a Pie Chart

If you know the percentage and the total, you can find the actual value:

Formula

  • Value = (Percentage Γ· 100) Γ— Total
  • Example: 25% of β‚Ή40,000 = (25 Γ· 100) Γ— 40,000 = β‚Ή10,000
Example 3: A pie chart shows that in a school of 500 students:
  • 40% like Cricket β†’ (40/100) Γ— 500 = 200 students
  • 25% like Football β†’ (25/100) Γ— 500 = 125 students
  • 15% like Badminton β†’ (15/100) Γ— 500 = 75 students
  • 10% like Kabaddi β†’ (10/100) Γ— 500 = 50 students
  • 10% like other sports β†’ (10/100) Γ— 500 = 50 students

Check: 200 + 125 + 75 + 50 + 50 = 500 βœ“

Choosing the Right Graph

Different graphs are best for different types of data. Choosing the right graph helps communicate information clearly.

Type of GraphBest ForExamples
Pictograph Showing data with pictures; simple comparisons for younger audiences Favourite fruits, number of books read, vehicles on road
Bar Graph Comparing quantities across different categories Marks in subjects, population of cities, favourite sports
Line Graph Showing change over time (trends, rise and fall) Temperature over a week, plant growth, stock prices, COVID cases
Pie Chart Showing parts of a whole (how a total is divided) Budget breakdown, how you spend your day, exam score distribution
Image needed: A visual guide showing 4 mini-examples side by side β€” a small pictograph, a small bar graph, a small line graph, and a small pie chart. Under each, a short label: "Pictograph: Compare with pictures", "Bar Graph: Compare categories", "Line Graph: Change over time", "Pie Chart: Parts of a whole".
Style: Clean infographic style, 4-column layout, colourful icons/mini-graphs, child-friendly
Size: 800Γ—350px
Quick Quiz β€” Which graph would you use?
  • To show how Mumbai's temperature changed in January β†’ Line Graph
  • To show how many students like each subject β†’ Bar Graph
  • To show how Arjun divides his pocket money β†’ Pie Chart
  • To show how many birds of each type were seen in a park β†’ Pictograph or Bar Graph
  • To show India's GDP growth over 10 years β†’ Line Graph

Finding the Range

The range of a data set tells us how spread out the values are. It is the difference between the highest (maximum) value and the lowest (minimum) value.

Formula

  • Range = Highest Value βˆ’ Lowest Value
Example 1: Marks of 8 students: 45, 72, 58, 90, 63, 81, 55, 68
Highest = 90, Lowest = 45
Range = 90 βˆ’ 45 = 45
Example 2: Temperature in Jaipur over 5 days: 38Β°C, 42Β°C, 35Β°C, 40Β°C, 37Β°C
Highest = 42Β°C, Lowest = 35Β°C
Range = 42 βˆ’ 35 = 7Β°C
Example 3: Runs scored by Virat Kohli in 6 IPL matches: 32, 85, 14, 63, 101, 48
Highest = 101, Lowest = 14
Range = 101 βˆ’ 14 = 87 runs
(A large range means the performance varied a lot!)
Think About It: If the range is very small (like 3 or 4), it means all values are close together. If the range is very large, it means the values are spread out widely. For example, if all students scored between 75 and 80, the range is only 5 β€” very consistent! But if scores are from 25 to 98, the range is 73 β€” very spread out.

Word Problems β€” Data in Real Life

Problem 1: The bar graph shows the number of students in 5 sections of Class 5:
Section5-A5-B5-C5-D5-E
Students4238454035

Questions:

  • Which section has the most students? β†’ 5-C (45)
  • Which section has the fewest? β†’ 5-E (35)
  • Total students in Class 5? β†’ 42 + 38 + 45 + 40 + 35 = 200
  • How many more students does 5-A have than 5-B? β†’ 42 βˆ’ 38 = 4
  • Range of students across sections? β†’ 45 βˆ’ 35 = 10
Problem 2: Akriti recorded the maximum temperature of her city for 6 months:
MonthJanFebMarAprMayJun
Max Temp (Β°C)222532384340

Questions:

  • Which graph type is best to show this data? β†’ Line Graph (shows change over time)
  • In which month was the temperature highest? β†’ May (43Β°C)
  • Between which two months did temperature rise the most? β†’ March to April (32β†’38, rise of 6Β°C)
  • Did the temperature always increase? β†’ No, it dropped from May (43Β°C) to June (40Β°C)
  • Range = 43 βˆ’ 22 = 21Β°C
Problem 3: A pie chart shows how 60 students of Class 5 travel to school:
  • School bus: 40%
  • Walking: 25%
  • Auto-rickshaw: 20%
  • Bicycle: 10%
  • Car: 5%

Questions:

  • How many students come by school bus? β†’ (40/100) Γ— 60 = 24 students
  • How many walk to school? β†’ (25/100) Γ— 60 = 15 students
  • How many come by bicycle? β†’ (10/100) Γ— 60 = 6 students
  • How many more students use the bus than walk? β†’ 24 βˆ’ 15 = 9 students
  • What fraction of students come by car? β†’ 5% = 5/100 = 1/20
Problem 4 (IPL): The line graph shows India's score over the first 10 overs of a T20 match:
After Over12345678910
Total Score71825385258657890105

Questions:

  • In which over were the most runs scored? β†’ Over 5 (score went from 38 to 52, i.e., 14 runs)
  • In which over were the fewest runs scored? β†’ Over 6 (score went from 52 to 58, i.e., 6 runs)
  • What was the total score after 10 overs? β†’ 105 runs
  • What was the run rate (average runs per over)? β†’ 105 Γ· 10 = 10.5 runs per over

Key Words

TermMeaning
DataA collection of facts or numbers gathered for a purpose
FrequencyThe number of times a value appears in the data
Tally MarksStrokes used to count frequency; every 5th stroke crosses the previous four
PictographA graph that uses pictures/symbols to represent data
Key (Legend)Tells what each symbol in a pictograph represents
Bar GraphA graph that uses rectangular bars to compare data
ScaleThe number each unit on an axis represents
Line GraphA graph that uses points connected by lines to show change over time
Pie ChartA circular graph divided into slices showing parts of a whole
RangeHighest value minus lowest value in a data set
X-axisThe horizontal axis of a graph (usually categories or time)
Y-axisThe vertical axis of a graph (usually values/numbers)
TrendThe general direction of change (up, down, or flat)
PercentageA number out of 100 (used in pie charts)

Key Points to Remember

  • Data is information collected for a purpose. It must be organised before it can be represented.
  • A pictograph uses pictures with a key. Half a picture = half the key value.
  • A bar graph uses bars of equal width. Bar height/length = data value. Bars have equal gaps between them.
  • A line graph shows change over time. Points are connected by straight lines. Upward line = increase, downward = decrease.
  • A pie chart shows parts of a whole. The full circle = 100%. All slices must add up to 100%.
  • Use a bar graph to compare categories. Use a line graph to show trends over time. Use a pie chart to show how a total is split.
  • Range = Highest value βˆ’ Lowest value. It tells how spread out the data is.
  • Every graph needs a title, labelled axes, and a proper scale.
  • To find a value from a pie chart: Value = (Percentage Γ· 100) Γ— Total

Finished learning? Now test what you know!