´╗┐Teacher Sarah stands in a studio next to a large touchscreen. She has short brown hair and wears a blue shirt with a print that reads "Homework zone."

A chart appears on the large touchscreen. The columns read "Hundreds, tens, ones, decimal, tenths, hundredths, thousandths."

A caption reads "Teacher Sarah."

Sarah says HI, TVOKIDS.
I'M TEACHER SARAH.
AND TODAY, WE'RE
GOING TO TALK ABOUT
DIVIDING DECIMAL NUMBERS
BY POWERS OF TENTHS,
WHICH MEANS DIVIDING DECIMAL
NUMBERS BY TENTHS,
HUNDREDTHS, AND
THOUSANDTHS.
NOW I LIKE TO USE A
PLACE-VALUE CHART
TO HELP ME KEEP TRACK
OF MY THINKING.
LET'S TRY AN
EXAMPLE TOGETHER.
HERE WE HAVE THE NUMBER
FOUR AND TWO-TENTHS.

She points at the number 4.2, written under the ones, decimal and tenths columns.

She says NOW, SUPPOSE I WANTED TO
TAKE FOUR AND TWO-TENTHS
AND DIVIDE IT BY
ONE-HUNDREDTH.
I'M GOING TO SHOW
YOU A TRICK
THAT'S GOING TO MAKE
THIS REALLY SIMPLE.
ALL WE NEED TO DO
IS TAKE A LOOK AT
THE POWER OF TENTHS THAT
WE ARE DIVIDING BY.
IN THIS CASE IT IS
ONE-HUNDREDTH.
I NOTICE THAT ONE-HUNDREDTH
HAS TWO PLACES
TO THE RIGHT OF
THE DECIMAL.

She points at the number 0.01 and continues
SO, WHAT I'M
GOING TO DO NOW
IS I'M GOING TO
MOVE MY DECIMAL
IN MY FOUR AND
TWO-TENTHS
TWO PLACES OVER
TO THE RIGHT.

In the original number 4.2 she moves the decimal two places to the right and adds a 0 to form the number 420.

She says WHICH GIVES ME
A QUOTIENT
OF FOUR-HUNDRED
AND TWENTY.
NOW, DON'T BE
ALARMED.
THE REASON WHY WE'RE
GETTING A LARGER NUMBER
IS BECAUSE WE'RE
DIVIDING BY A NUMBER
THAT IS LESS THAN ONE.
SO, LET'S TRY ANOTHER
EXAMPLE TOGETHER.
WE'RE GOING TO TAKE OUR
FOUR AND TWO-TENTHS
AND THIS TIME WE'RE
GOING TO DIVIDE IT
BY ONE-THOUSANDTH.
SO, WE'RE GOING TO
DO THE SAME STEP.
TAKE A LOOK AT OUR
POWER OF TEN,
AND COUNT THE
NUMBER OF PLACES
TO THE RIGHT
OF THE ZERO.

She counts on the number 0.001 and says ONE, TWO, THREE.
THIS TELLS US THAT
WE NEED TO MOVE
OUR DECIMAL PLACE THREE
PLACES TO THE RIGHT.
ONE, TWO, THREE,
PUTTING IN THE
ZEROS AS WE MOVE.

She repeats the process but now moves the decimal 3 times, adding two zeroes to form the number 4200.

She says THERE WE HAVE FOUR
AND TWO-TENTHS
DIVIDED BY
ONE-THOUSANDTH
AS FOUR-THOUSAND
AND TWO-HUNDRED.
REMEMBER, WHEN YOU'RE
DIVIDING BY TENTHS,
HUNDREDTHS AND
THOUSANDTHS,
COUNT THE NUMBER OF
PLACES AFTER THE DECIMAL
AND MOVE THE DECIMAL
THAT MANY PLACES
TO THE RIGHT.
SEE YOU NEXT TIME.