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Adding Real Numbers Application

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    At the beginning of the week,
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    Stewart's checking account had a balance
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    of negative fifteen dollars and eight cents.
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    On Monday morning he deposited a check
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    for four hundred twenty-six dollars and ninety cents.
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    On Tuesday morning he deposited another check
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    for [one] hundred dollars.
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    How much was in Stewart's checking account
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    after the second deposit, so after both of these deposits right over here?
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    So, he starts off with a negative balance,
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    so a negative balance means
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    that he's overdrawn his checking account.
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    He actually owes the bank money now.
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    Luckily, he's now going to put some money in his bank account,
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    so he'll actually have a positive balance in his checking account.
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    So, he starts off with negative fifteen dollars and eight cents,
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    and then to that, he adds
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    four hundred twenty-six dollars and ninety cents.
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    And then he adds another hundred dollars.
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    So, he started off with negative fifteen dollars and eight cents,
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    and then to that, he adds four hundred twenty-six dollars
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    and ninety cents and a hundred dollars.
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    So, that's five hundred and twenty-six dollars and ninety cents.
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    And so, how much is he going to have in his bank account?
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    He started, owing fifteen dollars and eight cents,
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    and then he's going to add
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    five hundred twenty-six dollars and ninety cents.
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    So, one way to visualize it,
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    is if you think about it on the number line,
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    and this is zero right over here.
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    He starts off at negative fifteen-point-zero-eight,
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    but then he's going to add
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    five hundred and twenty-six dollars [and ninety cents].
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    This is fifteen-point-zero-eight to the left,
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    that's how much he owes,
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    and to that, he's going to add
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    five hundred and twenty-six [dollars and ninety cents].
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    So, I'm not drawing this to scale,
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    but to that he's going to add
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    five hundred and twenty-six dollars and ninety cents.
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    So, the amount that he's going to be in the positive
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    is going to be
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    five hundred twenty-six dollars and ninety cents,
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    minus the fifteen-point-zero-eight.
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    And, so, essentially it's going to be this length right over here,
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    that's how much he's going to be in the positive,
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    That's going to be five hundred twenty-six dollars and ninety cents,
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    minus fifteen dollars and eight cents.
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    So, that's going to be--
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    and we can even just rewrite this
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    so that it actually looks exactly like that.
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    That's the exactly the same thing as
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    five hundred twenty-six dollars and ninety cents,
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    minus--
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    minus--
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    adding a negative is the same thing
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    as subtracting a positive--
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    minus fifteen-point-oh-eight.
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    --I will do this in another color--
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    Five hundred and twenty-six dollars and ninety cents,
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    minus fifteen dollars and eight cents.
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    Let's see, zero is less than eight,
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    let's make that a ten and borrow from this nine,
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    so that becomes an eight--
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    or I guess you could say, we are regrouping--
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    Everything up here is larger than everything there,
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    so ten minus eight is two,
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    eight minus zero is eight,
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    we have our decimal.
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    Six minus five is one.
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    Two minus one is one,
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    and then you have five minus nothing.
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    So, he is left
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    with five hundred eleven dollars and eighty-two cents,
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    after his second deposit.
Title:
Adding Real Numbers Application
Description:

Knowledge encountered:

Addition and Subtraction
Number line
Positive and Negative numbers

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Video Language:
English
Duration:
03:15

English subtitles

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