- WE WANT TO WRITE THE GIVEN
NUMBER IN DECIMAL FORM,
WHICH MEANS WE MUST BE FAMILIAR
WITH THE PLACE VALUE CHART
PROVIDED HERE.
OUR NUMBER IS TWENTY-ONE
HUNDREDTHS.
SO THE FIRST THING TO RECOGNIZE
HERE IS THE PLACE VALUE
WILL BE THE HUNDREDTHS
NOT THE HUNDREDS.
THE HUNDREDS PLACE VALUE IS
TO THE LEFT OF THE DECIMAL,
BUT THE HUNDREDTHS IS TO
THE RIGHT OF THE DECIMAL.
SO WE'RE TALKING ABOUT A NUMBER
THAT DEALS WITH THESE
PLACE VALUES HERE.
THE NEXT THING
THAT MIGHT BE HELPFUL
IS TO WRITE THIS AS A FRACTION.
TWENTY-ONE HUNDREDTHS WOULD BE
21 OVER A DENOMINATOR OF 100,
WHICH IN DECIMAL FORM
WOULD HAVE TO BE
TWO DIGITS TO THE RIGHT
OF THE DECIMAL, AS WE SEE HERE.
SO THIS WOULD BE .21
OR 21 HUNDREDTHS,
WHICH IS SOMETIMES
WRITTEN AS 0.21.
BUT OF COURSE HAVING ZERO
IN THE ONES PLACE VALUE
DOES NOT CHANGE
THE VALUE OF THE DECIMAL.
HERE WE HAVE
FIFTEEN THOUSANDTHS.
SO AGAIN, LOOKING AT
THE PLACE VALUE CHART,
NOTICE THE THOUSANDTHS OCCURS
THREE DIGITS TO THE RIGHT
OF THE DECIMAL.
SO OUR NUMBER WILL HAVE
TO CONTAIN THREE DIGITS
TO THE RIGHT OF THE DECIMAL,
SO WE'LL BE DEALING WITH THIS
PART OF THE PLACE VALUE CHART.
AND AGAIN, IT MAY BE HELPFUL TO
WRITE THIS AS A FRACTION FIRST.
FIFTEEN THOUSANDTHS WOULD BE
15 WITH A DENOMINATOR OF 1,000,
WHICH IN DECIMAL FORM
MUST HAVE THREE DIGITS
TO THE RIGHT OF THE DECIMAL.
SO IT WOULD BE .015,
THERE'S THE 15,
AND WE HAVE
THE THOUSANDTHS PLACE VALUE,
OR AGAIN IF WE WANT TO HAVE
A ZERO IN THE ONES PLACE VALUE,
THAT WOULD BE OKAY, TOO.
LET'S TAKE A LOOK
AT ONE MORE EXAMPLE.
HERE WE HAVE TWENTY-ONE
AND ONE HUNDRED THIRTY-SEVEN
TEN THOUSANDTHS.
THIS "AND"
REPRESENTS THE DECIMAL.
SO FOR THIS NUMBER,
WE'RE GOING TO HAVE DIGITS
TO THE RIGHT AND LEFT
OF THE DECIMAL.
THE NUMBER TWENTY-ONE
WILL HAVE DIGITS
IN THE TENS AND ONES
PLACE VALUE,
AND THEN WE HAVE ONE HUNDRED
THIRTY-SEVEN TEN THOUSANDTHS.
WELL, THE TEN THOUSANDTHS
PLACE VALUE
IS FOUR DIGITS TO THE RIGHT
OF THE DECIMAL,
SO WE'LL USE ALL OF
THE PLACE VALUES OUT TO HERE.
LET'S FIRST WRITE THIS
AS A FRACTION.
WE WOULD HAVE 21,
AND THEN WE'D HAVE 137/10,000.
SO THE FRACTION OR MIXED NUMBER
WOULD LOOK LIKE THIS.
SO IN DECIMAL FORM,
WE'D HAVE 21,
THEN OUR DECIMAL POINT,
AND THEN 137/10,000,
SO WE'LL HAVE TO HAVE A 0137
IN ORDER TO HAVE FOUR DIGITS
TO THE RIGHT OF THE DECIMAL.
ANOTHER NICE REASON TO WRITE IT
AS A FRACTION FIRST IS,
NOTICE HOW WE HAVE
FOUR ZEROS HERE
AND FOUR DIGITS TO THE RIGHT
OF THE DECIMAL.
IN THE PREVIOUS EXAMPLE, WE HAD
THREE ZEROES IN THE DENOMINATOR,
AND WE HAD THREE DIGITS
TO THE RIGHT OF THE DECIMAL.
AND IN THE FIRST EXAMPLE, WE HAD
TWO ZEROES IN THE DENOMINATOR
AND TWO DIGITS
TO THE RIGHT OF THE DECIMAL.
