[cheerful upbeat music] ♪ DID YOU KNOW THERE ARE 86,400 SECONDS IN A DAY?

HOW DO WE KNOW THIS?

MATH!

THANKS FOR SPENDING 1,800 OF THEM WITH US.

HERE'S TODAY'S MATH LESSON.

♪ ♪ HI, MATHEMATICIANS.

MS. NABORS HERE.

I NEED YOUR HELP TO SOLVE A MATH PROBLEM.

WILL YOU PLEASE HELP ME?

YOU WILL?

THANKS SO MUCH.

HERE'S MY PROBLEM.

A FRIEND HAS CHALLENGED ME TO MAKE SOME SHAPES, AND THEY GAVE ME ALL THESE COOL SHAPES, JUST LIKE YOU CAN SEE HERE.

THE CHALLENGE IS, THE SHAPES THAT MY FRIEND GAVE ME ARE NOT THE ONES THEY WANT ME TO MAKE.

I'M NOT SURE WHAT TO DO.

SO, I'M GLAD WE CAN THINK THROUGH THIS PROBLEM TOGETHER.

HERE ARE ALL OF THE SHAPES THAT MY FRIEND GAVE TO ME.

DO YOU KNOW THE NAMES OF ANY OF THEM?

OH, YOU'RE RIGHT.

I HEARD SOMEONE SAY THAT THEY SEE 3 TRIANGLES.

NICE WORK.

WHAT ELSE DO YOU SEE?

AWESOME.

I HEARD SOMEONE ELSE SAY THAT THEY SEE 2 SQUARES.

GREAT WORK.

WHAT OTHER SHAPES DO YOU NOTICE?

YES, I ALSO NOTICE THAT THERE IS A RHOMBUS.

GREAT JOB.

MY FRIEND HAS GIVEN ME 3 CHALLENGES, AND EACH ONE INVOLVES AT LEAST ONE OF THESE SHAPES.

LET'S LOOK AT THE FIRST ONE.

ARE YOU READY?

GREAT.

LET'S GO.

HERE IT IS.

USE 2 TRIANGLES TO MAKE A SQUARE.

HMM.

BEFORE WE GET STARTED, I'M WONDERING IF YOU CAN HELP ME FIGURE OUT WHICH OF THESE SHAPES ARE TRIANGLES.

WHICH ONES DO I USE?

OH, I HEARD SOMEONE SAY THAT THE BLUE SHAPES ARE TRIANGLES.

BUT HOW DO WE KNOW THE BLUE SHAPES ARE TRIANGLES?

WHAT ATTRIBUTES DOES A TRIANGLE HAVE?

OKAY, I HEARD SOMEONE SAY THAT THEY'RE NOT SURE THAT THEY REMEMBER WHAT THE WORD "ATTRIBUTE" MEANS.

THAT'S OKAY.

LET'S TALK ABOUT IT.

AN EXAMPLE WOULD BE THAT A SQUARE HAS 4 SIDES.

SO, THE NUMBER OF SIDES IS ONE OF A SHAPE'S POSSIBLE ATTRIBUTES.

THERE ARE OTHER ATTRIBUTES THAT A SHAPE CAN HAVE, SUCH AS SIDE LENGTHS, NUMBER OF ANGLES, AND TYPES OF ANGLES.

OKAY.

SO WITH THAT IN MIND, TELL ME, WHAT IS ONE ATTRIBUTE OF A TRIANGLE?

THAT'S RIGHT, ONE ATTRIBUTE OF A TRIANGLE IS THAT IT HAS 3 SIDES.

WE CALL A SHAPE A TRIANGLE IF IT IS CLOSED, MEANING ALL THE SIDES CONNECT AT A VERTEX, AND THE SHAPE HAS 3 SIDES.

WHEN I LOOK AT THESE SHAPES, I CAN SEE THAT EACH HAS 1, 2, 3 SIDES.

OKAY, NOW WE'RE CONVINCED THAT THESE ARE THE TRIANGLES THAT WE'LL NEED FOR THIS CHALLENGE.

WE KNOW THAT WE HAVE TO USE THESE TRIANGLES TO MAKE A SQUARE.

HOW WILL WE KNOW HOW TO USE THE TRIANGLE TO MAKE A SQUARE?

WAIT, THAT BRINGS UP ANOTHER QUESTION.

HOW DO WE KNOW A SHAPE IS A SQUARE, ANYWAY?

DO YOU KNOW?

WHISPER IT TO ME.

THAT'S RIGHT.

I HEARD SOMEONE SAY THAT WE CAN CALL A SHAPE A SQUARE IF IT HAS 4 RIGHT ANGLES, OR SQUARE CORNERS, AND 4 EQUAL SIDES.

WHEN WE LOOK AT A SQUARE, WE CAN SEE IT HAS EQUAL SIDES, BECAUSE EACH SIDE MEASURES 3 UNITS LONG.

THE SHAPE ALSO HAS 4 RIGHT ANGLES, BECAUSE WE CAN MAKE A SQUARE AT THE VERTICES.

SO, THAT'S HOW WE KNOW THAT A SQUARE IS A SQUARE, SO TO SPEAK.

HMM.

SO, NOW THAT WE HAVE THAT STRAIGHT, HOW CAN WE USE THESE TRIANGLES TO MAKE A SQUARE?

HMM.

LET'S PLAY AROUND WITH THE TRIANGLES AND SEE IF WE CAN FIGURE IT OUT.

IF I JUST PLACE THE 2 TRIANGLES NEXT TO EACH OTHER, WILL THAT MAKE A SQUARE?

NO, THEY WON'T.

YOU CAN SEE THAT PLACING THE TRIANGLES NEXT TO EACH OTHER WITHOUT MOVING THEM AROUND WON'T MEET OUR ATTRIBUTES FOR A SQUARE.

SO, THAT WON'T WORK.

OH, I KNOW.

WHAT IF I ROTATE THEM TO FORM A SQUARE?

DO YOU THINK THAT WILL WORK?

LET'S ROTATE THE TRIANGLES AND FIND OUT.

BINGO.

WHEN I ROTATE THE TRIANGLES SO THAT THEY MEET AT THEIR DIAGONALS, I CAN THEN SLIDE THEM TOGETHER TO FORM A SQUARE.

SO, THAT MEANS THAT 2 TRIANGLES PUT TOGETHER IN A CERTAIN WAY CAN INDEED MAKE A SQUARE.

OH, THAT REMINDS ME OF SOMETHING ELSE I NOTICED WHEN STARTING WITH A SQUARE AND THINKING ABOUT HOW TO CREATE TRIANGLES FROM IT.

LOOK WHAT HAPPENS IF I CUT A SQUARE IN HALF.

CUTTING A SQUARE INTO HALVES MEANS TO SPLIT INTO 2 EQUAL PARTS.

WHAT DO YOU SEE?

WHEN I CUT THE SQUARE VERTICALLY OR HORIZONTALLY, I MAKE 2 RECTANGLES.

BUT WHEN I CUT THE SQUARE IN HALF DIAGONALLY, I HAVE 2 TRIANGLES.

I CAN ALSO CALL THIS "DECOMPOSING," OR BREAKING APART A SHAPE.

JUST LIKE YOU CAN DECOMPOSE A NUMBER SUCH AS 10 INTO 6 AND 4, 5 AND 5, OR 2 AND 8, WE CAN DECOMPOSE SHAPES INTO SMALLER SHAPES.

SOMETIMES WHEN I DECOMPOSE A SQUARE, I GET 2 RECTANGLES, AND SOMETIMES, I GET 2 TRIANGLES, DEPENDING ON HOW I DECOMPOSE THE SHAPE.

LET'S SEE WHAT OTHER SHAPES WE CAN MAKE BY LOOKING AT ANOTHER CHALLENGE.

HERE IT IS.

WE KNOW WHAT A TRIANGLE IS.

HOW ABOUT A RHOMBUS?

WHAT MAKES A SHAPE A RHOMBUS?

TALK TO A FRIEND OR A TRUSTED ADULT ABOUT YOUR THINKING, AND THEN WHISPER IT TO ME.

I'LL WAIT.

OH, THAT'S SOME GREAT THINKING I'M HEARING OUT THERE.

SOMEONE SAID THAT THEY THINK THAT A RHOMBUS IS ACTUALLY VERY SIMILAR TO A SQUARE.

THAT'S RIGHT.

FOR BOTH THE RHOMBUS AND THE SQUARE, ALL 4 SIDES ARE EQUAL.

SO THEN, WHAT'S THE DIFFERENCE BETWEEN A RHOMBUS AND A SQUARE?

LOOK AT THE 2 SHAPES ON THE SCREEN AND WHISPER TO ME WHAT YOU NOTICE.

THAT'S RIGHT.

REMEMBER, A SQUARE HAS ALL EQUAL ANGLES, WHILE A RHOMBUS HAS OPPOSITE EQUAL ANGLES.

A RHOMBUS IS A SHAPE WITH 4 EQUAL SIDES, SO WE CAN SAY A SQUARE IS A RHOMBUS, BECAUSE IT HAS 4 EQUAL SIDES, AND THE OPPOSITE ANGLES ARE EQUAL, BUT A RHOMBUS IS NOT ALWAYS A SQUARE, BECAUSE ALL OF ITS ANGLES ARE NOT EQUAL.

HOW ABOUT A TRAPEZOID?

WHAT MAKES A SHAPE A TRAPEZOID?

A QUADRILATERAL IS A SHAPE WITH EXACTLY 4 SIDES.

AND WHEN SIDES ARE "PARALLEL," THAT MEANS THEY WILL NEVER INTERSECT.

WE CAN SEE THAT THE TOP AND BOTTOM SIDES OF THE TRAPEZOID WILL NEVER INTERSECT, SO WE CALL THEM "PARALLEL."

OKAY, NOW WE UNDERSTAND THE SHAPES WE'RE WORKING WITH.

LET'S THINK ABOUT HOW WE CAN MAKE A TRAPEZOID USING A RHOMBUS AND TRIANGLE.

THINKING BACK TO WHEN WE USED THE TRIANGLES TO MAKE A SQUARE, WE FOUND OUT THAT WE CAN CUT A SQUARE IN HALF TO OBTAIN 2 TRIANGLES.

SO, THAT MAKES ME WONDER, COULD WE DO THAT WITH A TRAPEZOID?

COULD WE CUT THE TRAPEZOID INTO HALVES TO GET A RHOMBUS AND A TRIANGLE?

SHARE YOUR THOUGHTS WITH A FRIEND OR A TRUSTED ADULT, AND THEN WHISPER THEM TO ME.

I AGREE WITH YOU.

I DON'T THINK IT WILL WORK.

IF WE CUT THE TRAPEZOID IN HALF VERTICALLY, WE DO NOT SEE A RHOMBUS OR A TRIANGLE.

IF WE CUT THE TRAPEZOID IN HALF HORIZONTALLY, WE ALSO DO NOT SEE A TRIANGLE OR RHOMBUS.

SO, IT LOOKS LIKE WE'LL HAVE TO TRY A DIFFERENT STRATEGY.

WHAT IF WE PLACE A RHOMBUS ON TOP OF A TRAPEZOID?

I WONDER IF THAT COULD HELP US DETERMINE HOW TO USE THE TRIANGLE AND RHOMBUS TOGETHER TO MAKE THE TRAPEZOID.

SHOULD WE TRY IT?

WE SHOULD.

OKAY, LET'S GO.

WOW, THAT FITS PERFECTLY.

THAT MEANS THAT A RHOMBUS IS A SHAPE THAT WE CAN USE TOGETHER WITH ANOTHER SHAPE TO MAKE THE TRAPEZOID.

LET'S SEE.

WHAT SHAPE COULD FIT NEXT TO THE RHOMBUS?

YOU'RE RIGHT, THE TRIANGLE FITS.

THIS MEANS THAT WE CAN DECOMPOSE, OR BREAK APART, A TRAPEZOID INTO A RHOMBUS AND A TRIANGLE.

THAT ALSO MEANS WE CAN USE A RHOMBUS AND A TRIANGLE TO COMPOSE A TRAPEZOID.

CHALLENGE MET AND SOLVED.

EXCELLENT THINKING.

LET'S LOOK AT THE LAST CHALLENGE.

HERE IT IS.

SQUARES AND RECTANGLES ARE SIMILAR, BECAUSE THEY BOTH HAVE RIGHT ANGLES AND 4 SIDES.

SO, WHAT'S THE DIFFERENCE BETWEEN A RECTANGLE AND A SQUARE?

I WAS WONDERING THAT, TOO.

TALK TO A FRIEND OR A TRUSTED ADULT ABOUT YOUR THINKING, AND THEN WHISPER IT TO ME AGAIN.

OH, I'M HEARING SOME GREAT THINKING.

LET ME SHARE SOME OF THAT WITH YOU.

I HEARD SOMEONE SAY THAT THEY NOTICE A DIFFERENCE IN THE COLORS OF THE 2 SHAPES.

THIS IS TRUE.

THIS RECTANGLE AND THIS SQUARE ARE INDEED DIFFERENT COLORS.

I'M WONDERING IF THERE'S ANOTHER ATTRIBUTE THAT WE CAN LOOK AT BESIDE THE COLOR TO DETERMINE THE DIFFERENCES BETWEEN THE RECTANGLE AND THE SQUARE.

OH, SOMEONE ELSE SAID THAT WE COULD LOOK AT THE SIDES.

WE KNOW THAT BOTH OF THESE SHAPES HAVE 4 SIDES, SO, THE NUMBER OF SIDES DOESN'T SEEM TO HELP US DETERMINE HOW THEY'RE DIFFERENT.

WHAT ELSE CAN WE LOOK AT?

THAT'S RIGHT.

WE CAN LOOK AT THE LENGTHS OF THE SIDES, NOT JUST THE NUMBER OF SIDES OF EACH SHAPE.

THAT'S WHERE WE'LL SEE THE DIFFERENCE.

IF YOU LOOK AT THE SQUARE, WE CAN SEE THAT ALL 4 SIDES ARE EQUAL.

IS THIS TRUE FOR THE RECTANGLE?

NOPE.

"OPPOSITE SIDES" ARE SIDES THAT ARE ACROSS FROM EACH OTHER.

IN THE RECTANGLE, WE CAN SEE THAT 2 OF ITS SIDES MEASURE 4 UNITS LONG, AND 2 OF ITS SIDES MEASURE 3 UNITS LONG.

THOSE SIDES ARE OPPOSITE FROM EACH OTHER.

A SQUARE ALSO HAS EQUAL OPPOSITE SIDES, SO IT CAN ALSO BE CALLED A RECTANGLE.

BUT CAN A RECTANGLE BE CALLED A SQUARE, THOUGH?

NO.

NOW THAT WE KNOW THE DIFFERENCE BETWEEN OUR 2 SHAPES, HOW CAN WE MAKE A RECTANGLE USING 2 SQUARES?

THIS ONE'S PRETTY SIMPLE.

IF I PLACE 2 SQUARES TOGETHER, I CAN MAKE ONE RECTANGLE.

EVEN THOUGH ALL OF THE SIDES ARE EQUAL, IS THIS SHAPE STILL A RECTANGLE?

WHY?

RIGHT.

THINK ABOUT WHAT WE JUST TALKED ABOUT.

THE OPPOSITE SIDES ARE EQUAL TO EACH OTHER, SO, YES, THESE 2 SQUARES MAKE 1 RECTANGLE.

WHOA, I FEEL LIKE I LEARNED SO MUCH ABOUT SHAPES WITH YOU.

THANK YOU SO MUCH FOR YOUR HELP.

TODAY, WE SOLVED 3 DIFFERENT CHALLENGES, AND WE DID IT BY WORKING TOGETHER AND USING WHAT WE KNEW ABOUT THE ATTRIBUTES OF SHAPES TO SOLVE PROBLEMS.

WE CAN DECOMPOSE SHAPES JUST LIKE WE CAN DECOMPOSE NUMBERS.

TODAY, I WANT YOU TO FIND SOMETHING THAT'S RECTANGULAR AROUND YOUR HOUSE OR ENVIRONMENT AND SPOT THE 2 TRIANGLES IN IT.

THEN TRY TO SPLIT A PIECE OF PAPER IN HALF TO FORM 2 TRIANGLES.

YOU CAN FIND SHAPES EVERYWHERE.

SEE YOU NEXT TIME.

HEY, FRIENDS, CHECK OUT THIS AMAZING VIDEO I JUST FOUND.

YOU'RE GOING TO LOVE IT.

GROWNUPS!

IT'S LIKE THEY THINK THEY RUN THE PLACE.

[band playing] ♪ ♪ ♪ YEAH ♪ ♪ UH-UH ♪ THIS GOES OUT TO... YOU KNOW, PARENTS.

WE'RE GONNA HAVE FUN ON THIS ONE.

YO!

♪ WHEN I WOKE UP THE OTHER DAY ♪ ♪ I THOUGHT I SAW A STRANGER SLEEPING NEXT TO ME ♪ ♪ AND I GOT SCARED ♪ ♪ ISN'T THIS WHERE YOU'RE SUPPOSED TO LAY?

♪ ♪ YEAH, BUT WHEN I OPENED UP MY EYES ♪ ♪ TO MY SURPRISE, YOU WERE NOT THERE ♪ ♪ NO, YOU GOTTA LET HIM GO ♪ ♪ I DON'T WANT TO HEAR YOUR LAME EXCUSES ♪ ♪ THE SAME I HEARD BEFORE ♪ ♪ I SAID, NO, YOU GOTTA LET HIM GO ♪ ♪ HOW CAN WE GET TOGETHER WHEN I KNOW ♪ ♪ HUH!

SOMEBODY'S SLEEPING IN MY BED?

♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY... ♪ ♪ I THOUGHT YOU'RE SUPPOSED TO BE ASLEEP ♪ ♪ HAH, BUT THEN I SAW YOU CRAWLING ♪ ♪ ALL ABOUT THE BED WHEN IT GOT DARK ♪ ♪ WEREN'T WE ALL JUST COUNTING SHEEP?

♪ ♪ GIRL, I THINK YOU LET ANOTHER SHEPHERD ♪ ♪ CRAWL HIS WAY INTO YOUR HEART ♪ ♪ NO ♪ ♪ YOU GOTTA LET HIM GO ♪ ♪ I DON'T WANNA HEAR YOUR LAME EXCUSES ♪ ♪ THE SAME I HEARD BEFORE ♪ ♪ I SAID NO ♪ ♪ PLEASE LET HIM GO ♪ ♪ AND I'M GONNA TELL YOU WHY, UHH!

♪ ♪ GIRL, YOU CAN'T DENY WE USED TO ♪ ♪ HOLD EACH OTHER TIGHT ♪ ♪ LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA-LA ♪ ♪ KISSIN', SQUEEZIN', TOUCHIN' ♪ ♪ ALL LATE INTO THE NIGHT ♪ ♪ LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA ♪ ♪ LA-LA-LA-LA-LA-LA ♪ ♪ OH, YOU GOTTA LET HIM GO ♪ ♪ I DON'T WANT TO HEAR YOUR LAME EXCUSES ♪ ♪ THE SAME I HEARD BEFORE ♪ ♪ I SAID, NO, YOU GOT TO LET HIM GO ♪ ♪ HOW CAN WE GET TOGETHER WHEN I KNOW ♪ ♪ SOMEBODY'S SLEEPING IN MY BED?

♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ GET UP OUT OF MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ SLEEPING IN MY BED ♪ ♪ LA-LA-LA-LA-LA ♪ ♪ LA-LA-LA ♪ [cheering] DID YOU KNOW THE AVERAGE YAWN LASTS 6 SECONDS?

1, 2, 3... 4, 5, 6.

NEXT TIME YOU YAWN, COUNT AND SEE HOW LONG IT LASTS.

BUT YOU WON'T BE YAWNING ANYTIME SOON, 'CAUSE WE HAVE A SUPER COOL MATH LESSON FOR YOU.

THIS WILL HELP COUNT DOWN THOSE SECONDS.

♪ ♪ HI, MATHEMATICIANS.

IT'S ME, MS. ALTMAN, AND IT'S AMAZING TO SEE YOU.

I'M SO EXCITED ABOUT SHOWING YOU A NEW MATH STRATEGY TODAY, WHERE WE WILL USE THE FACTORS THAT WE KNOW TO SOLVE A PROBLEM.

BEFORE WE GET STARTED, LET'S TAKE 20 SECONDS TO GRAB SOME SUPPLIES THAT WE WILL NEED FOR OUR TIME TOGETHER TODAY.

YOU WILL NEED PAPER AND A PENCIL.

I'M GOING TO GO AND GET MINE.

WHY DON'T YOU GO AHEAD AND DO THE SAME?

SEE YOU IN A LITTLE BIT.

♪ ♪ OH, MY GOODNESS!

CAN YOU BELIEVE THAT I HAVE TO COMPLETE INVENTORY OF ALL OF THESE CANS?

CAN YOU HELP ME WITH THE INVENTORY?

OH, THAT'S A GREAT QUESTION.

WHAT IS "INVENTORY"?

"INVENTORY" MEANS TO MAKE AN ORGANIZED LIST OF ITEMS.

IT TELLS YOU HOW MANY AND THE TYPE OF ITEMS THAT YOU HAVE.

IN THIS CASE, I HAVE TO COMPLETE INVENTORY OF THE CANNED GOODS.

[groans] I'M GONNA BE HERE ALL DAY!

THERE'S VEGETABLES, FRUIT, AND EVEN SOUP IN CANS!

DO YOU THINK WE COULD USE A MATH STRATEGY TO HELP US INVENTORY ALL OF THESE CANS?

WHAT'S THAT?

MULTIPLICATION MIGHT HELP US WITH INVENTORY?

THAT'S AN EXTRAORDINARY IDEA.

TODAY WE'RE GOING TO LEARN A NEW MULTIPLICATION STRATEGY WHERE WE WILL USE KNOWN FACTS TO HELP US SOLVE MULTIPLICATION PROBLEMS.

THIS STRATEGY IS SIMILAR TO BREAKING APART, OR "DECOMPOSING," A FACTOR.

YOU MAY HAVE LEARNED THIS STRATEGY IN SCHOOL.

IF YOU DIDN'T LEARN THIS STRATEGY IN SCHOOL, NO WORRIES.

I HAVE A VIDEO OF THIS STRATEGY ON THE PBS-NC YOUTUBE CHANNEL.

JUST ASK A TRUSTED ADULT FOR PERMISSION TO GET ON THE INTERNET, SO YOU CAN VIEW THAT VIDEO.

USING KNOWN FACTS MEANS THAT WE CAN USE THE MULTIPLICATION FACTS THAT WE IMMEDIATELY KNOW TO HELP US SOLVE FACTS THAT WE DON'T KNOW YET.

THINK OF IT AS MENTAL MATH, WHERE WE DON'T HAVE TO DRAW PICTURES OR MAKE ARRAYS, BECAUSE WE KNOW THE FACTS... [snaps fingers] JUST LIKE THAT, AND WE CAN USE THEM TO HELP US SOLVE THE ONES WE DON'T KNOW YET.

FOR EXAMPLE, A LITTLE BIRDIE TOLD ME THAT YOU KNOW ALL OF YOUR 5s MULTIPLICATION FACTS.

SINCE I KNOW MY 5s MULTIPLICATION FACTS JUST LIKE... [snaps fingers] THAT, I CAN USE THEM TO HELP ME WITH OTHER MULTIPLICATION FACTS THAT I DON'T KNOW YET.

LET'S REVIEW THE 5s MULTIPLICATION FACTS TOGETHER.

I WILL SAY THE FACTOR, AND I WANT YOU TO SAY THE PRODUCT WITH ME.

AS I SAY THE FACTORS, YOU WILL SEE AN ARRAY ON THE SCREEN.

GREAT JOB, MATHEMATICIANS.

KEEP SAYING THOSE PRODUCTS WITH ME.

NOW THAT WE HAVE REVIEWED OUR 5s MULTIPLICATION FACTS, LET'S USE THE FACTS THAT WE KNOW, LIKE OUR 5 FACTS, OR OTHER FACTORS THAT WE IMMEDIATELY KNOW, TO HELP US SOLVE MULTIPLICATION PROBLEMS.

ARE YOU READY?

GREAT.

LET'S GET STARTED.

TAKE A LOOK AT THESE CANS.

MY SUPPLY LIST SAYS THAT I HAVE 7 TYPES OF CANNED SOUPS, AND THERE ARE 9 KINDS OF EACH TYPE.

MM!

THAT'S A LOT OF DELICIOUS SOUP.

I CAN THINK OF THIS AS HAVING 7 GROUPS WITH 9 CANS IN EACH GROUP, OR 7x9.

HOW CAN I SOLVE THIS PROBLEM?

WHAT IS 7x9?

YES, WE COULD DRAW PICTURES OF EQUAL GROUPS OR BUILD AN ARRAY, BUT IS THERE A WAY TO SOLVE THIS PROBLEM USING MENTAL MATH, OR...

THE STRATEGY FOR THIS LESSON, USING KNOWN FACTS?

I'M SORRY?

CAN YOU REPEAT THAT?

DO YOU MIND IF I SHARE THAT WITH OUR OTHER MATH FRIENDS?

GREAT.

ONE OF OUR MATHEMATICIANS STATED, THEY'RE NOT SURE ABOUT THEIR 9 FACTS YET.

THEY ARE STILL PRACTICING THESE FACTS AND WANT TO KNOW IF THEY CAN USE A FACT THAT THEY IMMEDIATELY KNOW TO HELP THEM SOLVE 7x9.

WHAT'S THAT?

OH, SOMEONE SAID THEY KNOW THEIR 5s FACTS, AND WE JUST REVIEWED THEM, SO USING OUR 5s CAN HELP US.

THAT'S A GREAT IDEA!

LET'S USE OUR 5 FACTS THAT WE KNOW JUST LIKE... [snaps fingers] THAT TO HELP US FIND THE PRODUCT FOR 7x9.

OH, WAIT, SOMEONE HAD A QUESTION.

SOMEONE ASKED, HOW CAN WE USE OUR KNOWN 5 FACTS TO HELP US THINK ABOUT THE PRODUCT OF 7x9?

HMM.

WELL, LET'S THINK ABOUT THE DIFFERENT WAYS THAT WE CAN BREAK APART THE FACTOR 9 AND SEE IF USING THE FACTS THAT WE KNOW-- IN THIS CASE, THE 5 FACTS-- CAN HELP US SOLVE 7x9.

I'LL GIVE YOU SOME TIME TO THINK ABOUT THAT.

TURN AND TALK TO A FRIEND OR A TRUSTED ADULT.

WHAT ARE ALL THE DIFFERENT WAYS THAT WE CAN BREAK APART THE FACTOR 9?

THAT'S RIGHT!

WE CAN BREAK APART THE FACTOR 9 INTO... ...AND SO ON.

WOW!

THAT IS A LOT OF WAYS TO BREAK APART THE FACTOR OF 9.

WHICH WAY SHALL WE PICK?

THAT IS, WHICH WAY SHALL WE BREAK APART THE 9 FACTOR SO WE CAN SOLVE 7x9 AND USE OUR 5 FACTS TO HELP US?

YES!

WE CAN BREAK APART THE 9 INTO 4 AND 5.

THAT WILL HELP US USE OUR KNOWN 5 FACTS TO SOLVE THE PROBLEM.

LET'S REWRITE 7x9 AS 7x5 PLUS 7x4.

OKAY, NOW THAT WE TALKED ABOUT THAT, LET'S CONTINUE THINKING THROUGH THIS PROBLEM.

I KNOW THAT 7x5 IS THE SAME AS 35.

AND I KNOW THAT 7x4 IS THE SAME AS 28.

NOW I CAN ADD THE PRODUCTS OF 7x5, WHICH IS 35, AND 7x4, WHICH IS 28, TOGETHER, TO ANSWER OUR PROBLEM OF 7x9, WHICH IS 63.

GREAT JOB, EVERYONE.

AS WE TRANSITION OVER TO OUR NEXT PROBLEM, I WOULD LIKE TO INVITE YOU TO STAND UP, OR SIT UP TALL.

WE'RE GOING TO TAKE A QUICK MOVEMENT BREAK THAT I LIKE TO CALL "TAKE 5."

YOU CAN EITHER TAKE 5 HOPS, 5 STOMPS, 5 CLAPS, 5 STRETCHES, OR 5 FREESTYLES.

I'M GOING TO TAKE 5 CLAPS.

NOW, IT'S YOUR TURN.

1, 2, 3... 4, 5.

GREAT JOB!

LET'S TRY ANOTHER PROBLEM AND SEE IF WE CAN USE A KNOWN FACT TO HELP US OUT.

HOW ABOUT 6x8?

ARE THERE ANY FACTS THAT YOU KNOW THAT CAN HELP US SOLVE 6x8?

OH, GREAT IDEA.

WE JUST DECOMPOSE 9 INTO 4 AND 5, SO YOU WANT TO USE 4s FACTS TO HELP US SOLVE 6x8.

LET'S REVIEW THE 4s MULTIPLICATION FACTS.

I WILL SAY THE FACTORS, AND I WANT YOU TO SAY THE PRODUCT WITH ME.

AS I SAY THE FACTS, YOU WILL SEE AN ARRAY ON THE SCREEN.

SO, LET'S USE OUR 4 FACTS NOW THAT WE KNOW THEM JUST LIKE... [snaps fingers] THAT TO HELP US THINK ABOUT THE PRODUCT OF 6x8.

WAIT, I'M CONFUSED.

HELP ME REMEMBER-- WHY CAN WE USE OUR KNOWN FACTS TO HELP US THINK ABOUT THE PRODUCT OF 6x8?

LET'S THINK ABOUT DIFFERENT WAYS THAT WE CAN BREAK APART THE FACTOR 8 THIS TIME AND SEE IF USING OUR KNOWN 4s FACTS IS AN OPTION.

TURN AND TALK TO A FRIEND OR A TRUSTED ADULT.

WHAT ARE ALL THE DIFFERENT WAYS THAT WE CAN BREAK APART THE FACTOR 8?

THAT'S RIGHT.

WE CAN BREAK APART THE FACTOR 8 INTO... ...AND SO ON.

WHICH WAY SHOULD WE PICK?

THAT IS, WHICH WAY SHALL WE BREAK APART THE 8 FACTOR SO WE CAN SOLVE 6x8 AND USE OUR 4s FACTS?

YES, WE CAN BREAK APART THE 8 INTO 4 PLUS 4.

THAT WILL HELP US USE OUR KNOWN 4s FACTS TO SOLVE THE PROBLEM.

LET'S REWRITE 6x8 AS 6x4 PLUS 6x4.

WHAT'S THAT?

AWESOME!

YOU KNOW THAT 6x4 EQUALS 24, AND WE ALSO KNOW THAT WE NEED ANOTHER GROUP OF 6x4, WHICH IS AGAIN EQUAL TO 24.

WHAT'S THAT?

GREAT!

WELL, KISS YOUR BRAIN AND BLOW IT OUT OF THIS WORLD.

POW!

YOU KNEW AHEAD OF TIME THAT 6x8 IS THE SAME AS HAVING 2 GROUPS OF 6x4.

THAT IS AWESOME!

NOW WE CAN ADD THE PRODUCTS OF 6x4, WHICH IS 24, AND 6x4, WHICH IS 24 AGAIN, TOGETHER TO ANSWER OUR PROBLEM OF 6x8, WHICH IS 48.

GREAT JOB, EVERYONE.

WAIT.

WHAT'S THAT?

YOU USED ANOTHER KNOWN FACT TO SOLVE THE PROBLEM, AND YOU WANT TO SHARE WHAT YOU DID?

AWESOME!

I'LL SHARE YOUR STRATEGY WITH EVERYONE.

SOMEONE SAID THAT THEY ALREADY KNEW 6x7 WAS THE SAME VALUE AS 42.

AND THEN THEY JUST ADDED ANOTHER GROUP OF 6.

DO YOU KNOW WHY OUR FRIEND ADDED ANOTHER GROUP OF 6?

THAT'S RIGHT.

THEY MULTIPLIED 6 GROUPS OF 7 TO GET 42, SO THEY NEEDED 1 MORE GROUP OF 6 TO MAKE 8 GROUPS OF 6, OR 48.

SO, LET'S LOOK AGAIN, FRIENDS.

ONE FRIEND MADE 2 GROUPS OF 6x4, USING THE FACTS THAT THEY KNOW.

ANOTHER FRIEND USED THE FACTS THAT THEY KNOW-- 6x7 EQUALS 42-- AND ADDED 6x1, USING THE FACTS THAT THEY KNOW.

BOTH STRATEGIES ARE CORRECT, AND THEY WERE MUCH EASIER FOR OUR FRIENDS, BECAUSE THEY WERE ABLE TO USE THE FACTS THAT THEY KNOW TO FIGURE OUT THE ONES THEY DIDN'T KNOW YET.

THANKS FOR JOINING ME TODAY.

I HOPE YOU HAD FUN LEARNING A NEW STRATEGY OF USING KNOWN FACTS TO SOLVE MULTIPLICATION PROBLEMS.

IT'S SIMILAR TO BREAKING APART A FACTOR, BUT INSTEAD OF BREAKING THE PROBLEM INTO SMALLER NUMBERS, YOU PURPOSEFULLY BREAK THE PROBLEM INTO FACTS THAT YOU KNOW.

JOIN ME NEXT TIME TO LEARN MORE MATH STRATEGIES.

BYE, MATHEMATICIANS!

FOR MORE INFORMATION, PLEASE VISIT... ♪ ♪ CAPTIONS BY FEATURE SUBTITLING www.featuresubtitling.com