GRE: Quant Vocabulary

Integers

Integers are the set of positive whole numbers, their negative counterparts, and 0. Whole numbers are the natural numbers/counting numbers with the addition of 0.

Number Line

A diagram that represents numbers as points on a line, demonstrating their relationship between each other. The number line reads left to right, with numbers getting larger the further right you go.

The 4 Artihmetic Operations

- Addition

- Subtraction

- Multiplication

- Division

Exponents

The number that is small and raised to show how many times to multiply the number it is indicated against by itself.

Roots

The reverse of exponents. They undo the exponent process. Even roots can only take positive values or zero. Odd roots can take zero, or positive/negative values.

Factorial

Product of all positive integers from 1 till n. Denoted by an exclamation point at the end of an integer.

Operations with Negatives

Two same signs next to each other (+ + or - - ) become a positive. Two different signs (+ - or - +) become a negative. When multiplying or dividing same signs, they make a positive but different signs make a negative.

PEMDAS

- Parantheses

- Exponents

- Multiplication

- Division

- Addition

- Subtraction

PEMDAS Trickiness

Always consider multiplication and division as one level, and addition and subtraction as one level. Whenever you encounter multiplication/division and addition/subtraction, you work from left to right.

# of Integers in an Interval

Last number - First number + 1

For inclusive, you include the numbers in the range. For exclusive, you would remove the numbers in the range and apply the formula exlcuding the range values.