Number System
TN TET Mathematics
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Overview
The Number System forms the backbone of primary mathematics and is a foundational topic for TN TET Paper I and Paper II. Questions from this topic test your understanding of whole numbers, integers, place value, divisibility rules, and finding HCF and LCM. Expect 3–5 direct questions, plus this knowledge underpins fractions, algebra, and word problems.
Mastery here means quick mental calculations during the exam. You must be fluent with divisibility tests (saves time on HCF/LCM problems), comfortable moving between number types, and confident with place value manipulation. Pedagogy questions may also ask how to teach these concepts to children—connecting abstract numbers to concrete understanding.
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Key Concepts
- **Natural Numbers (N)**: Counting numbers starting from 1. {1, 2, 3, 4, ...}. Zero is NOT included.
- **Whole Numbers (W)**: Natural numbers plus zero. {0, 1, 2, 3, ...}. Every natural number is a whole number.
- **Integers (Z)**: Whole numbers plus negative numbers. {..., -3, -2, -1, 0, 1, 2, 3, ...}. Includes positive integers, negative integers, and zero.
- **Place Value vs Face Value**: Face value is the digit itself. Place value = digit × position value. In 4,725: the face value of 7 is 7, but its place value is 700.