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Rounding to the nearest tenth and hundredth

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    - [Instructor] Joey used
    0.432 pounds of cheese
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    to make mac-and-cheese for dinner,
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    and we could also call this
    432/1,000 pounds of cheese
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    to make mac-and-cheese for dinner.
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    Round the amount of cheese
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    to the nearest tenth.
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    So the amount of cheese once again
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    is 0.432 pounds
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    and just remember the places here.
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    This is 4/10,
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    so that's the tenths place.
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    This is the hundredths place,
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    and that's an S there,
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    so tenths, hundredths,
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    and this right over here is thousandths,
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    thousandths place.
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    So we wanna round to the nearest tenth.
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    So we're gonna round to the nearest tenth.
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    We go one place to the right.
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    If it's five or larger,
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    we round up.
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    This would become a five.
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    If it's less than five,
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    well, if it's less than five,
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    which is the case here,
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    we're gonna round down to just 4/10 even.
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    So because three is less than five,
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    we are going to round down,
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    and we're going to get 0.400,
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    or we could write that as 0.4,
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    or we could write that as 4/10 of a pound.
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    Let's do another one.
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    Eliza's pet snail traveled
    2.197 meters in one day.
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    Round the distance to
    the nearest hundredth.
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    So pause this video and
    see if you can do that.
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    Round the distance to
    the nearest hundredth.
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    So it's 2.197.
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    This is the hundredths
    place right over here,
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    and so if we're gonna round
    to the nearest hundredth,
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    we're gonna go one place to the right.
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    If this one place to the right
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    is five or greater,
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    we're gonna round up,
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    and seven is five or greater,
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    so we are going to round up .
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    Now this is interesting
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    'cause if you round a nine up,
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    you get to 10,
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    but you can't put a
    whole 10 right over here.
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    So one way to think about it
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    is you have a 19 here,
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    and so if you round up,
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    you're gonna go to a 20,
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    or another way to think about it.
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    If you round the nine up,
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    you're gonna go to the next tenth.
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    So this is going to be 2 point,
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    you could view this as 19/100
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    or 19/100 and 7/1,000,
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    and so now we're gonna round up
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    to 20/100,
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    so 2.20.
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    We're rounding to the nearest hundredth,
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    which you could write as 2.2,
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    but to make it clear
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    that you're rounding to
    the nearest hundredth,
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    you're gonna write 2.20,
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    and later in your life,
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    this actually might matter
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    to actually show what you're rounding to.
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    Let's do another example here.
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    Cassandra spends 6.75
    hours each day at school.
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    Round the amount of time
    to the nearest hour.
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    Alright, so 6.75,
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    so you might be a little confused,
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    and actually, I encourage
    you to pause the video again
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    and try to solve it on your own.
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    So you might be a little confused
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    'cause they're not saying
    round it to the nearest tenth
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    or hundredth or one or 10 or 100.
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    They're saying to the nearest hour,
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    but in this case,
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    the hour is the ones place.
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    So if we're gonna round
    to the nearest hour,
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    this is another way of saying
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    round to the nearest one.
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    So we're gonna round to the nearest one.
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    We go one place to the right.
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    We go to look at the tenths place.
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    If it's five or larger,
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    we round up.
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    Well, seven is five or larger,
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    so we round up to the next hour,
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    which is going to be seven,
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    so seven hours.
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    If this was 6.49999,
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    once again, if we're
    rounding to the nearest hour,
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    we go one place to the right.
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    It doesn't matter that we
    have all these nines here.
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    We'd say, hey, look,
    four is less than five.
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    Therefore, we should round down,
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    round down,
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    and you would round down to the next hour.
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    Well, the next hour that's below 6.499999,
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    nine, nine, nine, nine,
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    is six hours,
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    but in this case, we had a
    seven in the tenths place,
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    which is definitely greater
    than or equal to five,
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    and so we'd round up to the next hour,
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    which is seven hours.
Title:
Rounding to the nearest tenth and hundredth
Description:

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Video Language:
English
Team:
Khan Academy
Duration:
04:32

English subtitles

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