Day 2

Algebra: Chapter 1-1

Symbols and Expressions

In algebra, we use symbols to stand for various numbers. One type of symbol is called a VARIABLE. An expression such as 396 ÷ v and contains at least one variable is called an ALGEBRAIC EXPRESSION. We can replace a variable with a number, this is called SUBSTITUTING for the variable.

Sets of numbers:

• Natural: 1, 2, 3, 4, 5, …
• Whole: 0, 1, 2, 3, 4, 5, …
• Rational: numbers which include natural and whole numbers and can be expressed as a RATIO such as 1/1 or 2/3

Parenthesis (, ) or [,] or {,} are called GROUPING SYMBOLS and we do things in them first.

PEMDAS, please excuse my dear aunt sally – order of operations. Just like in Language Arts, we have a convention of writing/reading from left to right, we have a convention in math.
We do things in the order of:

1. parenthesis
2. exponents
3. multiplication/division (in order from left to right)
4. addition/subtractions (also in order from left to right).

Intro to Algebra: Chapter 1-1

See above