Number sets | Fractions | Pre-Algebra | Khan Academy

Number Sets

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Pre-Algebra on Khan Academy: No way, this isn't your run of the mill arithmetic. This is Pre-algebra. You're about to play with the professionals. Think of pre-algebra as a runway. You're the airplane and algebra is your sunny vacation destination. Without the runway you're not going anywhere. Seriously, the foundation for all higher mathematics is laid with many of the concepts that we will introduce to you here: negative numbers, absolute value, factors, multiples, decimals, and fractions to name a few. So buckle up and move your seat into the upright position. We're about to take off!

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[meep]

This is a lot more complex than meets the eye and contradictory

[pvkeditss]

y’all posted this on my first birthday lol. also what about numbers like 1.6 aren’t they natural counting numbers?

[TheBeardedMathMan]

this is such a hard, dry, topic to teach.

[bauerfrederick]

helps me in my incoming math test tomorrow! THX

[rexonakhatoon]

Thank you Sir for such nice explanation

[AwkwardAndAwesome]

So if "real" numbers include pretty much everything, does that mean there are any "unreal" numbers?

[Wormytoby]

Pi isn't exactly 22/7, that's just what it's simplified to sometimes. It can't truly be written as a fraction :)

[durdonaanvarova]

I really liked your explanation thanks

[Rahul-xfez]

Like Tabitha Buckley said pi isn't exactly 22/7.Then we can't take pi as a rational number.We can't make pi as a a fraction.

[jaedond]

thank you so much. this really helped me with my math quiz

[doctorpoopypants]

Thank god i left my notebook in my locker

[vivekkumaryadav]

so if real number include pretty much everything dose that mean there nechural number

[RTRVII]

@kulpreetg there's only price for the second I'm sorry.

[McBoogs]

It was interesting until I heard "so on and so forth" 3 Times within 30 secs.

[BobMcCoy]

It's pretty much the crap you learn in the beginning of the term

[AwkwardAndAwesome]

Nevermind... I posted that comment halfway through the video. =P

[kulpreetg]

do i get i prize? for being first and third

[tobydufour]

This video is a lie many people would argue that 0 is not included into any of these categories and its a ongoing discussion and therefore should not be included into this video