I've been searching everywhere on Khan Academy for this: What is a natural number, and is there a place on KA where I can find something about this?

The natural numbers are all whole numbers, excepting 0. 0 is a whole number but not a natural number because it does not have a positive or negative value.

why is -5 not a whole number its is a type of number ?

Whole numbers are numbers which are not FRACTIONS , DECIMALS or NEGATIVES. They are numbers from 1 to Infinity and 0. [0, 1, 2, 3 ...] While -5 is neither a FRACTION nor a DECIMAL , it is still a NEGATIVE for which it is not a WHOLE number. Negative Non-Fractional,Non-Decimal numbers are not whole numbers. Only Positive Non-Fractional,Non-Decimal numbers are whole numbers including Zero. Integers are the numbers which include both WHOLE numbers and their NEGATIVES (Non-Fractional,Non-Decimal Negatives). [... -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 ...] So -5 obviously falls under that category. Therefore, -5 is an Integer , not a Whole number ! Hope it helps !

what type of number is .33%

It is rational. A percent that is equal to .0033 as a decimal and 33/10000 as a fraction.

Are all square rooted numbers irrational?

Not all square roots are irrational like the square of 9 is three or the square root of 16 is 4 but a lot of numbers are irrational. The square root of a number is if it multiplies by self to get that number. (Like 5*5=25 and the square root of 25 is 5). I hope that makes sense!!

Ummm... Am i the only one that had to take notes because it was kind of challenging for me?

Taking notes is always a good idea!

what are non terminating numbers?

They are numbers like pi, √2, etc. When you express these numbers in decimals, they never stop. These are called irrational numbers. Also, infinity is also not terminating. (Technically, it's not a number. It's just a statement that the number is getting bigger.)

Would it be accurate to say that whole numbers are positive numbers and zero?

This is partially correct. The whole numbers are the positive *integers* and zero. (Note that for example, 1/2 is a positive number that is not a whole number.) Have a blessed, wonderful day!

Why is the fraction 22/7 rational if put into decimal form it is not?

22/7, which is a ratio of two integers, is rational whether it is written in fraction or decimal form. The decimal form of 22/7 is the *repeating* decimal 3.142857142857... and so is still rational. Only the value, and not the form, determines whether a real number is rational or irrational. While pi is irrational, this does not contradict the fact that 22/7 is rational, because the decimal form of pi (that is, 3.14159265358979323...) does not exactly match the decimal form of 22/7. Note that 22/7 is only an *approximation* of pi. Have a blessed, wonderful day!

Main content

8th grade

Course: 8th grade > Unit 1

Lesson 3: Irrational numbers

Classifying numbers review

Google Classroom

Review whole numbers, integers, rational, and irrational numbers. Then, practice identifying each.

Whole numbers

Whole numbers

are numbers that do not need to be represented with a fraction or decimal. Also, whole numbers cannot be negative. In other words, whole numbers are the counting numbers and zero.

Examples of whole numbers:

$4, 952, 0, 73$ ‍

Integers

Integers

are whole numbers and their opposites. Therefore, integers can be negative.

Examples of integers:

$12, 0, - 9, - 810$ ‍

Rational numbers

Rational numbers

are numbers that can be expressed as a fraction of two integers.

Examples of rational numbers:

$44, 0. \overset{―}{12}, - \frac{18}{5}, \sqrt{36}$ ‍

Irrational numbers

Irrational numbers

are numbers that cannot be expressed as a fraction of two integers.

Examples of irrational numbers:

$- 4 π, \sqrt{3}$ ‍

How are the types of number related?

The following diagram shows that all whole numbers are integers, and all integers are rational numbers. Numbers that are not rational are called irrational.

Want to learn more about classifying numbers? Check out this video.

Practice

Problem 1

What type of number is $\sqrt{5}$ ‍?

Want to try more problems like this? Check out these exercises:
Classify numbers: rational & irrational
Classifying numbers

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Redapple8787
Posted 6 years ago. Direct link to Redapple8787's post “I've been searching every...”
I've been searching everywhere on Khan Academy for this: What is a natural number, and is there a place on KA where I can find something about this?
Button navigates to signup pageComment on Redapple8787's post “I've been searching every...”
(49 votes)
Answer
- Logan Herr
  Posted 5 years ago. Direct link to Logan Herr's post “The natural numbers are a...”
  The natural numbers are all whole numbers, excepting 0. 0 is a whole number but not a natural number because it does not have a positive or negative value.
  Comment on Logan Herr's post “The natural numbers are a...”
  (70 votes)
pedetin2015
Posted 5 years ago. Direct link to pedetin2015's post “why is -5 not a whole num...”
why is -5 not a whole number its is a type of number ?
Button navigates to signup pageComment on pedetin2015's post “why is -5 not a whole num...”
(13 votes)
Answer
- Sidharth Sunil
  Posted 5 years ago. Direct link to Sidharth Sunil's post “Whole numbers are numbers...”
  Whole numbers are numbers which are not FRACTIONS , DECIMALS or NEGATIVES.
  They are numbers from 1 to Infinity and 0. [0, 1, 2, 3 ...]
  
  While -5 is neither a FRACTION nor a DECIMAL , it is still a NEGATIVE for which it is not a WHOLE number.
  
  Negative Non-Fractional,Non-Decimal numbers are not whole numbers.
  Only Positive Non-Fractional,Non-Decimal numbers are whole numbers including Zero.
  
  Integers are the numbers which include both WHOLE numbers and their NEGATIVES (Non-Fractional,Non-Decimal Negatives). [... -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 ...]
  So -5 obviously falls under that category.
  
  Therefore,
  -5 is an Integer , not a Whole number !
  
  Hope it helps !
  Comment on Sidharth Sunil's post “Whole numbers are numbers...”
  (40 votes)
Pierre Tétreau
Posted 5 years ago. Direct link to Pierre Tétreau's post “what type of number is .3...”
what type of number is .33%
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(9 votes)
Answer
- David Severin
  Posted 5 years ago. Direct link to David Severin's post “It is rational. A percen...”
  It is rational. A percent that is equal to .0033 as a decimal and 33/10000 as a fraction.
  Comment on David Severin's post “It is rational. A percen...”
  (27 votes)
Mehul prince
Posted 6 years ago. Direct link to Mehul prince's post “what are non terminating ...”
what are non terminating numbers?
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(6 votes)
Answer
- David Lee
  Posted 6 years ago. Direct link to David Lee's post “They are numbers like pi,...”
  They are numbers like pi, √2, etc. When you express these numbers in decimals, they never stop. These are called irrational numbers. Also, infinity is also not terminating. (Technically, it's not a number. It's just a statement that the number is getting bigger.)
  Comment on David Lee's post “They are numbers like pi,...”
  (19 votes)
StephenPianoMan
Posted 4 years ago. Direct link to StephenPianoMan's post “Are all square rooted num...”
Are all square rooted numbers irrational?
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(8 votes)
Answer
- C Ethan Smith
  Posted 4 years ago. Direct link to C Ethan Smith's post “Not all square roots are ...”
  Not all square roots are irrational like the square of 9 is three or the square root of 16 is 4 but a lot of numbers are irrational. The square root of a number is if it multiplies by self to get that number. (Like 5*5=25 and the square root of 25 is 5). I hope that makes sense!!
  Comment on C Ethan Smith's post “Not all square roots are ...”
  (7 votes)
Edumacated
Posted 5 years ago. Direct link to Edumacated's post “Would it be accurate to s...”
Would it be accurate to say that whole numbers are positive numbers and zero?
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(5 votes)
Answer
- Ian Pulizzotto
  Posted 5 years ago. Direct link to Ian Pulizzotto's post “This is partially correct...”
  This is partially correct. The whole numbers are the positive integers and zero. (Note that for example, 1/2 is a positive number that is not a whole number.)
  
  Have a blessed, wonderful day!
  Button navigates to signup page
  (8 votes)
Lexi
Posted 7 months ago. Direct link to Lexi's post “Ummm... Am i the only one...”
Ummm... Am i the only one that had to take notes because it was kind of challenging for me?
Button navigates to signup pageComment on Lexi's post “Ummm... Am i the only one...”
(7 votes)
Answer
- AuroraAlberts
  Posted 7 months ago. Direct link to AuroraAlberts's post “Taking notes is always a ...”
  Taking notes is always a good idea!
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  (4 votes)
LIAM705
Posted 5 months ago. Direct link to LIAM705's post “What is 100/100”
What is 100/100
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(5 votes)
Answer
- joeli8
  Posted 5 months ago. Direct link to joeli8's post “1 is the answer for 100/1...”
  1 is the answer for 100/100
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  (1 vote)
Queen Imogen
Posted 5 months ago. Direct link to Queen Imogen's post “Why is the fraction 22/7 ...”
Why is the fraction 22/7 rational if put into decimal form it is not?
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(2 votes)
Answer
- Ian Pulizzotto
  Posted 5 months ago. Direct link to Ian Pulizzotto's post “22/7, which is a ratio of...”
  22/7, which is a ratio of two integers, is rational whether it is written in fraction or decimal form. The decimal form of 22/7 is the repeating decimal 3.142857142857... and so is still rational. Only the value, and not the form, determines whether a real number is rational or irrational.
  
  While pi is irrational, this does not contradict the fact that 22/7 is rational, because the decimal form of pi (that is, 3.14159265358979323...) does not exactly match the decimal form of 22/7. Note that 22/7 is only an approximation of pi.
  
  Have a blessed, wonderful day!
  Comment on Ian Pulizzotto's post “22/7, which is a ratio of...”
  (12 votes)
emom4210
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hey guys I'm in 7 grade I have a test tomorrow so yeah
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- Dariely Carranza
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  Man, i feel bad 4 u
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  (4 votes)