Role of 0

• a + 0 = 0 + a = a, where a is a whole number, example, 2 + 0 = 0 + 2 = 2
• b + 0 = 0 + b = b, where b is an integer, example, -5 + 0 = 0 + (-5) = -5
• c + 0 = 0 + c = c, where c is a rational number, -2/7 + 0 = 0 + (-2/7) = -2/7
• Zero is called the identity for the addition of whole numbers, integers, rational numbers

Role of 1

• a × 1 = 1 × a = a, where a is a whole number, example, 2 × 1 = 1 × 2 = 2
• b × 1 = 1 × b = b, where b is an integer, example, -5 × 1 = 1 × (-5) = -5
• c × 1 = 1 × c = c, where c is a rational number, -2/7 × 1 = 1 × (-2/7) = -2/7
• 1 is called the multiplicative identity for whole numbers, integers, rational numbers