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Can you think of examples where 2 + 2 does NOT equal 4?

Like, for example, 2 gallons plus 2 quarts does NOT equal 4 gallons.

5 Answers

  • 2 months ago

    You can not add different units together. It's not that 2+2 doesn't equal 4. It is just that gallons plus quarts can not be added.

    Here are some mathematical instances when 2+2 is not 4.In base 3: 2+2 = 11In base 4: 2+2 = 10If two vectors of length 2 are added, the sum will be less than 4. 

    In algebra, 2X + 2 is not 4 or 4X. They can not be added.

    In Relativity, a speed of 2 hundred thousand km per sec plus 2 hundred thousand km per sec is not 4 hundred thousand km per sec. It is less. You must use the Relativistic velocity addition formula. 

  • Jim
    Lv 7
    2 months ago

    A change in number base, such as base 3 or base 4

    A change in units like 2 gals + 2 qts

    A change in systems such as 2 gals + 2 liters

    In human terms such as 2 couples having babies.

    Etc. for like a million (exaggeration) different ways.

  • 2 months ago

    in base 4:

    2₄ + 2₄ = 10₄

  • User
    Lv 7
    2 months ago


    You're using different units, which is sort of cheating.

    Another way of doing this is adding groups, collective nouns and the like.


    Consider: 2 flocks of birds (of the same species) combine with 2 flocks of birds (again: of the same species)

    2 flocks + 2 flocks = 1 flock

    There is a merger between two companies, the result being the forming of a new company

    1 company + 1 company = 1 company

    One company purchases another company and integrates it into the parent company.

    company A + company B = company A


    (many variations on the theme)

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  • 2 months ago

    your example is bad, you cannot add unlike terms.

    8 qt + 2 qt = 10 qt

    vectors are a real example. A force of 2 N east plus a  force of 2 E add to 2.8 N NE

    then there is the classic, where everything is rounded to 1 place

    2.4+2.4 = 4.8 when rounded is

    2 + 2 = 5

    or speeds approaching light speed.

    relativistic speed additionS = (v+u)/(1+vu/c²)

    let u and v be 2e8 m/s

    S = 4e8 / (1 + 4/9) = 2.7 m/s

    so 2e8 plus 2e8 = 2.7e8 m/s

    of course, non of these are actually 2 + 2 ≠ 4

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