(music plays)

Sarah stands next to a wall touch screen showing a definition. She is in her mid-twenties, with short straight brown hair. She wears a blue T-shirt with a print that reads "Home Work Zone" and black tights.

She says HEY, TVO KIDS.
I'M TEACHER SARAH.
AND TODAY, WE'RE GOING TO
TALK ABOUT RATIOS.
A RATIO IS A COMPARISON
BETWEEN ONE GROUP OF THINGS
TO ANOTHER GROUP OF THINGS,
OR BETWEEN ONE GROUP OF THINGS
TO ENTIRE GROUP OF THINGS.
A RATIO COMPARES VALUES.
IT TELLS YOU HOW MUCH
OF ONE THING THERE IS,
IN COMPARISON TO ANOTHER.

She clicks on a top menu and another screen shows an expanded version of the definition.

She continues A RATIO HAS TWO TERMS: THE FIRST
TERM AND THE SECOND TERM.
EACH TERM IN A RATIO
REPRESENTS A SPECIFIC AMOUNT.
WE CAN READ A RATIO BY SAYING
THREE TO FOUR.

She circles two dots and continues THIS LITTLE SYMBOL RIGHT HERE,
WE READ AS TO,
WHEN WE ARE TALKING
ABOUT RATIOS.
THERE ARE TWO DIFFERENT
PARTS OF RATIOS:
THE FIRST ONE
IS A PART TO PART RATIO.
A PART TO PART RATIO COMPARES
ONE SPECIFIC PART
TO ANOTHER PART.
SO LET'S TAKE A LOOK
AT THIS EXAMPLE.
I SEE THAT I HAVE STARS,
AND I ALSO HAVE CIRCLES.
SO, A PART TO PART RATIO
IN THIS CASE WOULD COMPARE
THE NUMBER OF STARS TO THE
NUMBER OF CIRCLES.
IN THIS CASE, I KNOW THAT MY
FIRST TERM REPRESENTS THREE,
BECAUSE THERE ARE THREE STARS.
AND IF I WANTED TO COMPARE
THE NUMBER OF STARS
TO THE NUMBER OF CIRCLES,
I NOW WOULD FIGURE OUT
HOW MANY CIRCLES I HAD.
COUNT THEM UP!
ONE, TWO, THREE, FOUR.
SO I HAVE FOUR CIRCLES.
NOW I CAN'T FORGET
MY LITTLE SIGN.
I WOULD READ THIS RATIO
AS THREE STARS TO FOUR CIRCLES.
LET'S TRY ANOTHER ONE TOGETHER.
HERE, I HAVE A WHOLE BUNCH OF
DIFFERENT SHAPES.
IN THIS CASE, MY PART TO PART
RATIO NEEDS TO COMPARE
TRIANGLES TO SQUARES. SO MY
FIRST TERM REPRESENTS TRIANGLES.
I'M GOING TO TAKE A LOOK TO SEE
HOW MANY TRIANGLES I HAVE.
AND THIS CASE, I ONLY HAVE ONE.
SO THE NUMBER OF TRIANGLES
I HAVE IS ONE.
THE NEXT THING I NEED TO DO IS
COUNT HOW MANY SQUARES I HAVE.
THAT'S THE NEXT PART
OF MY RATIO.
ONE, TWO, THREE,
FOUR, FIVE, SIX.
SO I HAVE SIX SQUARES. I CAN'T
FORGET TO DO MY LITTLE SYMBOL,
WHICH MEANS TO.
SO THE SECOND PART OF RATIO
IS A PART TO WHOLE RATIO.
THIS RATIO COMPARES
TO SPECIFIC PART TO THE WHOLE.
SO IN THIS CASE, A PART TO WHOLE
RELATIONSHIP WOULD SHOW
THE NUMBER OF STARS COMPARED
TO THE TOTAL NUMBER OF SHAPES.

Using her index fingers, she highlights the shapes and writes down the numbers metioned.

She continues SO FOR EXAMPLE, AGAIN, I HAVE MY
TWO TERMS AND MY RATIO.
THE FIRST TERM IS STARS,
BUT THIS TIME, THE SECOND TERM
REPRESENTS THE WHOLE,
WHICH IN THIS CASE IS ALL
SHAPES.
SO I START WITH MY FIRST TERM.
I CAN SEE THAT
I HAVE THREE STARS
SO THE VALUE OF MY FIRST TERM,
IN THIS PART TO WHOLE RATIO
IS THREE.
THE NEXT TERM, OR THE SECOND
TERM REPRESENTS ALL SHAPES.
SO NOW I NEED TO COUNT UP
AND SEE HOW MANY SHAPES
I HAVE ALTOGETHER.
ONE, TWO, THREE, FOUR,
FIVE, SIX, SEVEN.
SO THE SECOND TERM IN THIS RATIO
WOULD BE SEVEN.
AND I CAN'T FORGET MY TO SIGN.
SO IN THIS CASE,
MY PART TO WHOLE RATIO IS
THREE STARS TO SEVEN SHAPES.
LET'S TRY THE NEXT ONE.
IN THIS CASE, MY FIRST TERM TO
THE WHOLE PART OF RATIO
REPRESENTS TRIANGLES. NOW I KNOW
I ONLY HAVE ONE TRIANGLE.
SO THE VALUE OF MY FIRST TERM IN
THIS RATIO IS GOING TO BE ONE,
WRITE IN MY TO SIGN,
AND FOR MY SECOND TERM
I NEED TO COUNT UP
ALL MY SHAPES.
SO I COUNT UP ALL OF MY SHAPES,
I KNOW THAT I HAVE 14 SHAPES,
AND THEREFORE, MY PART TO WHOLE
RATIO IS ONE TO 14.
OR ONE TRIANGLE FOR
EVERY 14 SHAPES.
A FEW THINGS THAT
YOU NEED TO REMEMBER:
THE FIRST THING IS
THAT A RATIO COMPARES VALUES.
THE SECOND THING IS
THAT A RATIO HAS TWO TERMS.
EACH TERM IN THE RATIO
REPRESENTS A SPECIFIC VALUE
DEPENDING ON WHAT IT IS YOU'RE
WRITING THE RATIO FOR, OF COURSE
AND LASTLY, THERE ARE TWO TYPES
OF RATIOS:
PART TO PART RATIOS,
WHICH REPRESENTS ONE PART OF THE
RATIOS COMPARED TO ANOTHER PART.
AND PART TO WHOLE RATIOS,
WHICH REPRESENTS ONE PART
COMPARED TO THE ENTIRE THING.
THERE YOU HAVE IT, TVO KIDS.
RATIOS. SEE YOU NEXT TIME!