Tally marks
Also called: Four and cross method · Topic: Geographical Data: Sources, Compilation and Processing · NCERT: Class 12, Ch 1 "Data - Its Source and Compilation"
Meaning
Tally marks are a quick way to count items into classes while grouping data. You draw one small upright stroke for each item. Every fifth stroke is drawn across the four strokes before it, making a bundle of five. This is why it is called the "four and cross" method. Counting the bundles in fives makes the totals quick to read and lowers the chance of mistakes.
Example
When NCERT groups the geography scores of 60 students into ten classes, each score gets one stroke in its class row. A class with 7 scores shows one crossed bundle of five plus two single strokes.
Related concepts
- Grouping of data
- Class interval
- Frequency distribution
- Cumulative frequency
- Exclusive method
- Inclusive method
- Frequency polygon
- Ogive