Meaning 💡
Any collection of facts, numbers, measures, observations or other
descriptions of things that convey information about those things
is called DATA.
➡ We collect data, organise it, and present it visually
so we can understand and make inferences quickly!
① Collecting & Organising Data
🔎 First we collect data — e.g. asking classmates their favourite game.
📝 A simple list is hard to read → we organise it using a Frequency Table.
✏️ Tally marks are used to count: draw | for each item; on the 5th one, draw a line across the previous 4 → ||||
🔢 Frequency = number of times a value/observation occurs.
📐 Data can also be arranged in ascending/descending order to quickly find min, max & counts.
Example: Sweets chosen by students
Sweet
Tally Marks
No. of Students
Jalebi
|||| |
6
Gulab Jamun
|||| ||||
9
Gujiya
|||| |||| |||
13
Barfi
|||
3
Rasgulla
|||| ||
7
② Pictographs 🖼️
Definition
A pictograph represents data through pictures/symbols of objects —
helps answer questions about data at a quick glance, without writing numbers!
🔑 A Scale / Key tells us what one symbol represents — e.g. 😊 = 1 student or 😊 = 10 children
◐ A half symbol can represent half the scale value (e.g. half of 10 = 5)
📏 Categories can be arranged horizontally or vertically
⚠️ Challenge: hard to show numbers that are not exact multiples of the scale (like 33 or 27)
Example: Sleep survey ( 🔺 = 10 children )
Always → 5 symbols = 5×10 = 50 children
Sometimes → 2½ symbols = 20+5 = 25 children
Never → 4 symbols = 40 children
③ Bar Graphs 📊
Definition
Bar graphs use bars of uniform width with equal spacing between them.
The length/height of each bar shows the frequency of that category.
Draw 2 lines (horizontal + vertical)
➡
Mark categories (equal spacing)
➡
Choose a Scale
➡
Draw bars as per frequency height
📌 Scale = value represented by 1 unit length (e.g. 1 unit = ₹200, or 1 unit = 10 runs)
📌 Bars can be vertical (column graph) or horizontal
🏔️ Use vertical bars for heights (mountains, people) — grows upward like real life!
🌍 Use horizontal bars for lengths/distances parallel to ground (rivers, distances)
⬆️ Markings on the scale must always start from zero
Example: Monthly Expenses (scale: 1 unit = ₹200)
Item
Expense (₹)
Bar height (units)
House Rent
3000
15
Food
3400
17
Education
800
4
Electricity
400
2
④ Pictograph vs Bar Graph
Pictograph
Bar Graph
Uses pictures/symbols 🖼️
Uses bars of uniform width 📊
Fun & visual, but tricky for large data
Better for large / precise data
Needs a scale (symbol = n units)
Needs a scale (1 unit length = n)
⑤ Artistic Side & Infographics 🎨
🎨 Infographics = data + attractive visuals (colours, shapes, images) to communicate clearly
📐 Bars must always be kept the same width — only length/height should change
🚫 Caution: Making triangles/pictures bigger in all dimensions (not just height) can mislead the viewer!
✨ Good data presentation = Accurate + Visually Appealing
📌 Remember: A picture that "looks nice" isn't always correct — always check if the scale is followed properly before trusting an infographic!