The ISEE will directly and indirectly test your knowledge of number types. For example, a word problem may include rules where its values may only be integers or whole numbers.

Real Numbers (Numbers that Exists)

number-types-diagram

Natural Numbers

  • include positive numbers
  • do not include zero
  • do not include negative numbers
  • do not include decimals or fractions
Examples
      1, 2, 3, 4
      -2, 0, 2.5

Whole Numbers

  • includes positive numbers
  • includes zero
  • does not include negative numbers
  • does not include decimals or fractions
Examples
      0, 1, 2, 3, 4
      -4, -1.5, 3.7

Integers

  • includes positive numbers
  • includes zero
  • includes negative numbers
  • does not include decimals or fractions

Examples

        -2, -1, 0, 1, 2
        -4.3, -2.9, ½

Rational Numbers

  • any number that can be represented as a fraction

Examples

      -3, 4.25, 0.004
      √2, √3, π

Irrational Numbers

  • any number that cannot be represented as a fraction

Examples

      √2, √3, π
       3.14, 22/7

Imaginary Numbers (Numbers That Don’t Exist)

Imaginary Numbers

  • the square root (or even root) of a negative number
  • squaring a negative number results in a positive number, thus the square root of a negative number does not exist
  • generally represented as i = √-1

Examples

      √-2, 4√-25
      √7, √19

Complex Numbers

  • includes a real part (a) and an imaginary part (bi)
  • acts like a binomial in calculations
  • a + bi

Examples

       4 + 3i
      x3 – 3x = 14