Smart Charts
What is Data?
DATA is INFORMATION. It is facts and numbers that we COLLECT.
- How many students are ABSENT today
- What is your FAVOURITE colour
- How many cars PASS your house in 10 minutes
When we collect data, we can LEARN things and make DECISIONS.
Collecting Data
Step 1: Ask a Question
'What is the favourite fruit of students in our class?'
Step 2: Collect Information
Go around the class and ASK each student.
Step 3: Record the Data
Write down what everyone says.
Step 4: Organise the Data
Put the information in a TABLE so it is easy to read.
Tally Marks
Tally marks are a way of COUNTING using lines. Each line stands for ONE item.
Tally Mark Rules
| Number | Tally Mark |
|---|---|
| 1 | | |
| 2 | || |
| 3 | ||| |
| 4 | |||| |
| 5 | |
| 6 | |
| 7 | |
| 8 | |
| 9 | |
| 10 |
Remember: Every 5th mark goes ACROSS the previous four to make a GROUP of 5.
Practice Tally
Count the vowels in this sentence: 'I love my school.'
- A: || (2)
- E: | (1)
- I: | (1)
- O: ||| (3)
- U: | (1)
Pictographs
A PICTOGRAPH uses PICTURES or SYMBOLS to show data.
Example: Favourite Fruits
| Fruit | Number of Students | Pictograph |
|---|---|---|
| Mango | 10 | 🥭🥭🥭🥭🥭 |
| Apple | 6 | 🍎🍎🍎 |
| Banana | 4 | 🍌🍌 |
| Orange | 8 | 🍊🍊🍊🍊 |
Key: Each fruit picture = 2 students
So if you see 5 mango pictures, that means 5 × 2 = 10 students chose mango.
Making a Pictograph
- Choose a SYMBOL for your data
- Decide what EACH symbol represents (the KEY)
- Draw the correct NUMBER of symbols
- Label your pictograph clearly
Important!
Always include a KEY so everyone knows what each picture MEANS.
Key: 🚗 = 2 cars
Reading Charts and Tables
A TABLE organises data into ROWS and COLUMNS.
Example: Weather for One Week
| Day | Weather |
|---|---|
| Monday | ☀️ Sunny |
| Tuesday | ☀️ Sunny |
| Wednesday | ☁️ Cloudy |
| Thursday | 🌧️ Rainy |
| Friday | 🌧️ Rainy |
| Saturday | ☀️ Sunny |
| Sunday | ☀️ Sunny |
Questions:
- How many sunny days? → 5 days
- How many rainy days? → 2 days
- Was it cloudy on Wednesday? → Yes
Example: Toys in a Shop
| Toy | Number |
|---|---|
| Doll | 15 |
| Car | 20 |
| Ball | 12 |
| Teddy bear | 8 |
Questions:
- Which toy is most? → Car (20)
- Which toy is least? → Teddy bear (8)
- How many total toys? → 15 + 20 + 12 + 8 = 55
Bar Graphs
A BAR GRAPH uses BARS of different lengths to show data.
Parts of a Bar Graph
- X-axis (horizontal line): Shows what we are measuring
- Y-axis (vertical line): Shows the NUMBERS
- Bars: The HEIGHT of each bar shows the VALUE
Example: Students in Each Class
| Class | Number of Students |
|---|---|
| Class 1 | 40 |
| Class 2 | 35 |
| Class 3 | 45 |
| Class 4 | 30 |
| Class 5 | 38 |
In a bar graph:
- Class 3 has the TALLEST bar (45 students)
- Class 4 has the SHORTEST bar (30 students)
- The difference between Class 3 and Class 4: 45 - 30 = 15 students
Drawing a Bar Graph
- Draw a HORIZONTAL line (X-axis) — write the names
- Draw a VERTICAL line (Y-axis) — write numbers
- For each item, draw a BAR to the correct height
- Make all bars the SAME WIDTH
Making Your Own Chart
Activity: Favourite Colour Survey
Ask 10 classmates: 'What is your favourite colour?'
| Colour | Tally | Number |
|---|---|---|
| Red | || | 2 |
| Blue | 5 | |
| Green | | | 1 |
| Yellow | || | 2 |
Now draw a bar graph!
- Blue is the MOST popular (5 students)
- Green is the LEAST popular (1 student)
Activity: How We Come to School
| Mode of Transport | Tally | Number |
|---|---|---|
| Walk | 5 | |
| Bus | 7 | |
| Cycle | || | 2 |
| Car | | | 1 |
| Auto | || | 2 |
Practice Problems
Problem 1: Library Books
| Type of Book | Number |
|---|---|
| Story | 25 |
| Science | 15 |
| History | 10 |
| Poetry | 5 |
- How many story books? → 25
- Which type is least? → Poetry (5)
- Total books? → 25 + 15 + 10 + 5 = 55
Problem 2: Birthday Months
| Month | Number of Birthdays |
|---|---|
| Jan-Mar | 8 |
| Apr-Jun | 6 |
| Jul-Sep | 10 |
| Oct-Dec | 4 |
- Most birthdays in which months? → Jul-Sep (10)
- Least birthdays? → Oct-Dec (4)
- Total birthdays? → 8 + 6 + 10 + 4 = 28
Common Mistakes
-
'A pictograph does not need a key.' — A key is ESSENTIAL! Without it, no one knows what each symbol means.
-
'In a tally, 5 is written as |||||.' — No! For ease of counting, 5 is written as
||||(a group of 4 with a line across). -
'Bar graph bars can have different widths.' — No! All bars should be the SAME width. Only the HEIGHT should change.
-
'Tally marks and numbers are the same thing.' — They show the same INFORMATION, but tally marks are a way of COUNTING as you collect data.
-
'The tallest bar shows the smallest number.' — No! The TALLEST bar shows the LARGEST number. The shortest bar shows the smallest number.
Quick Self-Test
Q1: Write tally marks for 7.
A1: |||| || (a group of 5 plus 2 more).
Q2: In a pictograph, 🍎 = 4 apples. How many apples do 3 🍎 show? A2: 3 × 4 = 12 apples.
Q3: In a bar graph, what does the height of the bar show? A3: It shows the NUMBER or VALUE for that category.
Q4: What is the mode of your class birthday data? A4: (Depends on actual data — the month with most birthdays).
Q5: In a survey of favourite colours, 5 students chose blue, 3 chose red, 2 chose green. How many students were surveyed? A5: 5 + 3 + 2 = 10 students.
Q6: What is a pictograph? A6: A chart that uses pictures or symbols to show data.
Q7: Why do we use tally marks? A7: To easily count and keep track of data as we collect it.
Q8: In a table with 4 rows of data, how many categories are there? A8: There are 4 categories (one in each row).
