Types of numbers

“What different ways do people write and express numbers?”

In expanded form, standard form, and in word form.

WHAT IS THE DIFFERENCE?

Written form: An amount represented or shown by words.

Example: I have five hundred fifty-three Tomorrow by Together albums.

Standard form: An amount represented or shown using numbers.

Example: I have 553 Tomorrow by Together albums.

Expanded form: An amount represented using numbers to show the place value of each digit.

Example: I have 500+50+3 Tomorrow by Together albums./ I have 5×100+5×10+5×1 Tomorrow by Together albums.

(Grouping periods)

Review: Expanded Form

Expanded form - writing a number to show the value of each digit can be written as: 

1. The sum of each digit

2. The sum of each digit multiplied by its matching place value
   

91,013 = 90,000 + 1,000 + 10 + 3

= 9 ✕ 10,000 + 1 ✕ 1,000 + 1 ✕ 10 + 3 ✕ 1

Numbers: Are used to count, measure, and label.

There are many types of Numbers used in grade 8 math.

Natural numbers: Positive numbers

Integers: Natural numbers and their negatives, like (-1,-2,0,1,2, etc..)

Rational numbers: A between 2 integers such as, 2/3 or a decimal like 2.3.

Irrational: An Irrational number is a number that cannot be written as a fraction. Irrational numbers have lengthy decimals that continue without repeating

Example: Examples of irrational numbers include decimal numbers that never repeat or terminate (e.g., pi, 3.12212222122…) and square roots of non-perfect squares.