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.

### 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

• 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