What is Data?
Data is any collection of facts—such as numbers, words, measurements, or observations—that gives us information. For example, a list of your friends’ favourite games or the temperatures recorded over a week is data.
When data is first collected, it is often unorganized. To make sense of it, we need to organize it.
Organizing Data
Imagine a teacher wants to know the favourite sweets of students in a class. If he just writes down names as students shout them out, he gets a messy list: Jalebi, Gulab Jamun, Rasgulla, Jalebi, Jalebi, Barfi…
To organize this, we use a Table. We list the items (Sweets) in one column and the count (Number of Students) in another.
Tally Marks
Counting large amounts of data can be tricky. To avoid mistakes, we use Tally Marks.
Tip
Tally Mark System:
- We draw a vertical line
|for each count. - When the count reaches 5, we cross the previous four lines diagonally.
- This creates a group of 5:
||||crossed becomes a bundle.
This makes it easy to count in multiples of 5 (5, 10, 15…).
Visualizing Tally Marks
Frequency
The number of times a particular entry occurs is called its Frequency.
Example Table:
| Sweets | Tally Marks | Number of Students (Frequency) |
|---|---|---|
| Jalebi | ` | |
| Gulab Jamun | ` | |
| Barfi | ` |
By arranging data this way, we can quickly answer questions like “Which sweet is the most popular?” or “How many students prefer Barfi?”.