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Why does a negative divided by a negative equal a positive? Why does a negative divided by a positive equal a negative? Here's how I would explain it to a 7th grader.

51,420 views • 7 months ago •via X (Twitter)

22 Comments

diddie~drawer's profile picture
diddie~drawer7 months ago

Hard disagree…don’t use two different interpretations to explain same concept. It just confuses things.

Sean McClure's profile picture
Sean McClure7 months ago

To keep the mental model the same across both examples, always ask “how many steps to get to the numerator?” -8 / -2 …we apply “positive 4 steps” -8 / 2 …we apply “negative 4 steps” In the first example, the 2 is already negative, so we don’t need to change the step direction. In the second example, we do.

Tinker's profile picture
Tinker7 months ago

can a 7th grader understand partitive model

@thePitOfGravel's profile picture
@thePitOfGravel7 months ago

Your explanation may be confusing to a 7th grader. It may be better to make use of the 4 quadrants of the Cartesian plane. It will also help them with many other concepts later on.

Xara's profile picture
Xara7 months ago

Do not think in terms of number. For negative think in terms of direction always.

Barb; Grandmother's profile picture
Barb; Grandmother7 months ago

Do you have a class or series on khan academy or YouTube? Patreon?

白米's profile picture
白米7 months ago

I honestly believe that my school life would have been different if you had been my mathematics teacher….I mean I still would have been high in class, but you would have blown my mind. 🤣🤣🤣

mckennagene's profile picture
mckennagene7 months ago

That doesn't really hold up, there are -4 in each group in the partitive model? That seems like you just have to know when you are counting in the partitive model you are counting negative, but when you are counting in the first model you are counting positive.

Michael Allan's profile picture
Michael Allan7 months ago

I love this.

Howie Hua's profile picture
Howie Hua7 months ago

Thank you!

Road Runner 🇮🇳's profile picture
Road Runner 🇮🇳7 months ago

Ans to 8/(-2): measurement method We’ve to divide 8 positive elements into groups of (-2), which is not possible. However, we can divide 8 into groups of 2 = 4 Since 2 and -2 are complimentary, the elements in the group as well as the answer will be complimentary = -4.

Kimi Schmitz✨'s profile picture
Kimi Schmitz✨7 months ago

8 is my favorite number

Warren 🤓's profile picture
Warren 🤓7 months ago

all i could think of is - why can’t we use the same interpretation for both? are we to memorize which one is appropriate depending on what the signs are? i love the passion but this explanation is frankly more confusing

Vidya's profile picture
Vidya7 months ago

Not really good ..

John China man's profile picture
John China man7 months ago

I feel sorry for learners

Cathy Campbell's profile picture
Cathy Campbell7 months ago

I think I would be thinking of "the opposite of" to help.

leonoracohen's profile picture
leonoracohen7 months ago

Just followed you because of this video!! Thank you!! (I'm 40 years past seventh grade, BTW).

Owa Lundaaganya's profile picture
Owa Lundaaganya7 months ago

Applying the former logic to the latter problem, answer is zero. Wouldn't recommend this approach

OceanCool's profile picture
OceanCool7 months ago

Question how would this apply in a real life scenario! My questions for maths man

Venu Ananda's profile picture
Venu Ananda7 months ago

Nope. Absolutely makes no sense. Not the way to explain to a 7th grader at all.

Spanish for You!'s profile picture
Spanish for You!7 months ago

Love your videos! So much enthusiasm and such great explanations. You are a wonderful educator!

Tracey Schreier's profile picture
Tracey Schreier7 months ago

Please do multiplication of a negative by negative

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