Form 1 Mathematics

Key Topics with Simple Definitions & Examples

Natural Numbers

Definition: Numbers used for counting starting from 1, 2, 3...

Examples:

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8

Even Numbers

Definition: Numbers divisible by 2.

Examples:

  • 2
  • 4
  • 6
  • 8
  • 10
  • 12
  • 14
  • 16

Odd Numbers

Definition: Numbers not divisible by 2.

Examples:

  • 1
  • 3
  • 5
  • 7
  • 9
  • 11
  • 13
  • 15

Prime Numbers

Definition: Numbers greater than 1 that have only 1 and itself as factors.

Examples:

  • 2
  • 3
  • 5
  • 7
  • 11
  • 13
  • 17
  • 19

Decimal Numbers

Definition: Numbers with a fractional part separated by a decimal point.

Examples:

  • 0.1
  • 0.25
  • 0.5
  • 1.1
  • 2.75
  • 3.14
  • 4.5
  • 5.9

Whole Numbers

Definition: Natural numbers including zero.

Examples:

  • 0
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7

Rounding Off

Definition: Replacing a number with a nearby value having fewer digits.

Examples:

  • 3.67 → 3.7
  • 5.24 → 5.2
  • 12.58 → 13
  • 9.99 → 10
  • 7.49 → 7
  • 0.456 → 0.46
  • 123.89 → 124
  • 0.999 → 1

Simple Linear Equations

Definition: An equation of the form ax + b = 0, where x is unknown.

Examples:

  • x + 3 = 7 → x = 4
  • 2x + 5 = 9 → x = 2
  • 3x - 4 = 8 → x = 4
  • 5x + 10 = 35 → x = 5
  • 4x - 7 = 9 → x = 4
  • 6x + 2 = 20 → x = 3
  • x - 5 = 10 → x = 15
  • 2x - 3 = 7 → x = 5

Statistics

Definition: Collection, organization, analysis, and presentation of data.

Examples with Numbers:

  • Test scores of students: 78, 85, 92, 67, 74, 88, 91, 79
  • Daily temperature readings (°C): 22, 24, 25, 23, 26, 27, 24, 22
  • Population of a village over years: 1020, 1055, 1088, 1120, 1150, 1180, 1205, 1230
  • Number of books read per month: 3, 5, 2, 4, 6, 3, 5, 4
  • Sports scores in a league: 2-1, 3-0, 1-1, 0-2, 4-3, 3-2, 2-2, 1-0
  • Monthly rainfall data (mm): 120, 85, 90, 110, 95, 100, 130, 105
  • Height of students in class (cm): 150, 155, 160, 162, 158, 165, 170, 168
  • Number of cars passing a junction daily: 220, 250, 240, 230, 260, 270, 255, 245

LCM and HCF

Definition:

  • HCF (Highest Common Factor): The largest number that divides two or more numbers exactly.
  • LCM (Lowest Common Multiple): The smallest number that is exactly divisible by two or more numbers.

Examples with Numbers:

  • HCF of 12 and 18: 6
  • LCM of 12 and 18: 36
  • HCF of 24, 36, 60: 12
  • LCM of 24, 36, 60: 360

Examples with Variables:

  • HCF of a and b (where a = 8x, b = 12x): HCF = 4x
  • LCM of a and b (where a = 8x, b = 12x): LCM = 24x
  • HCF of p and q (where p = 15y, q = 25y): HCF = 5y
  • LCM of p and q (where p = 15y, q = 25y): LCM = 75y