Fractions — Class 6 Maths (Samacheer Kalvi)
TN State Board (Samacheer Kalvi) Class 6 Mathematics, Term 3 — Chapter 1. Working with parts of a whole.
1. About this chapter
This chapter covers types of fractions, equivalent fractions and simplest form, comparing fractions, mixed and improper fractions, and the four operations on fractions.
2. Types of fractions
- A fraction a/b has a numerator (a) and a denominator (b).
- Proper fraction: numerator < denominator (3/5). Improper fraction: numerator ≥ denominator (7/4). Mixed fraction: a whole number with a proper fraction (1¾).
- Like fractions have the same denominator (2/7, 5/7); unlike fractions have different denominators.
3. Equivalent fractions and simplest form
- Equivalent fractions have the same value, got by multiplying or dividing numerator and denominator by the same number: 1/2 = 2/4 = 3/6.
- Simplest form: divide both parts by their HCF (6/8 = 3/4).
4. Comparing fractions
- Like fractions: the one with the larger numerator is greater.
- Unlike fractions: make the denominators the same (LCM), then compare, or cross-multiply.
5. Operations on fractions
- Add/subtract like fractions: add/subtract numerators, keep the denominator (2/7 + 3/7 = 5/7).
- Add/subtract unlike fractions: convert to the same denominator (LCM) first.
- Multiply: multiply numerators and denominators (2/3 × 4/5 = 8/15).
- Divide: multiply by the reciprocal (2/3 ÷ 4/5 = 2/3 × 5/4 = 10/12 = 5/6).
6. Worked examples
Example 1. Reduce 12/18 to simplest form. HCF 6 → 2/3.
Example 2. Add 1/4 + 1/6. LCM 12 → 3/12 + 2/12 = 5/12.
Example 3. Convert 7/3 to a mixed fraction. 7 ÷ 3 = 2 remainder 1 → 2⅓.
7. Exercises (Samacheer Kalvi)
- Classify as proper, improper or mixed: 3/8, 9/4, 2½.
- Write two equivalent fractions of 3/5.
- Compare: (a) 3/7 and 5/7 (b) 2/3 and 3/4.
- Add 2/5 + 1/3 and subtract 5/6 − 1/4.
- Multiply 3/4 × 2/9 and divide 5/8 ÷ 1/2.
8. Common mistakes
- Mistake: Adding denominators when adding fractions. Fix: Keep (or equalise) the denominator; add only the numerators.
- Mistake: Forgetting to use the reciprocal when dividing. Fix: Divide = multiply by the reciprocal of the second fraction.
- Mistake: Not reducing to simplest form. Fix: Always simplify the final fraction using the HCF.
9. Quick revision
- Term 3 · Ch 1 · fractions.
- Proper (< 1), improper (≥ 1), mixed; like = same denominator.
- Equivalent fractions: × or ÷ both parts by the same number; simplest form via HCF.
- Add/subtract: same denominator (LCM); multiply across; divide = × reciprocal.
